I'm a graphic designer and prepress specialist. I've used Illustrator since version 1.1 on a Mac Plus (it came with a video tape with John Warnock himself showing you how to use it). I've used practically all the vector illustration tools that have come to market since. Thus, I have a pretty good idea about how such programs behave, and which were the ones for professional use and which were for dilettantes to make pretty pictures, but not for making a brand identity for a Fortune 500 company.
I bought the whole Affinity Suite with the hopes that I could cut the cord on Adobe's pay-us-every-month-or-else scheme. What you have created so far is to be commended and I see a lot of bright potential. I really, really, really love StudioLink, for instance. Its amazing. But, man... there is so much.
I am not making this topic to troll you. I am making it in the hopes that, from the perspective of someone who has done serious work for serious clients both on the creative end and the technical end, you guys can get some feedback to make both Designer and the whole suite something everybody wants to move to. My plan is to keep coming back to it and adding quirks, bugs, and major issues so that you can hone these apps. I hope to pay for upgrades with some of these things I say in them, and some things that are even better than what I suggest.
Soooo... lets start with color. Because its bad.
The problem is the paradigm. A person who is a web designer will have no issues with this, because it seems built to fit their needs. Make a quick graphic, mess around with the RGB sliders until its pretty, and your done. Professionals who work for big clients need their work to be repurposed to all media forms: web/screen, offset press, digital printing, signage, you name it. Thus, colors have to be carefully managed.
What Designer uses is a color mixing panel, and a Swatches panel that has lots of different palettes in it for you to dig around and play with. What it needs is a color mixing panel, and a Swatches panel that automatically, and only, shows used colors from the document, whose view is set it "small icon list" by default. If you mix up a color and use it, it shows up automatically in the Swatches panel under a "Document" palette. You can have your "Application" palette, but anything you choose from it needs to show up in that "Document" palette. Knowing what you are using will be your first clue that you have mixed colorspaces and have too many instances of a particular "spot color."
Graphic designers who have never worked on the technical side are horrendous with making graphics that will not separate correctly and come out with unexpected results when used in any medium other than on-screen display. One time I had some students come to my work and they brought their best artwork with them. I loaded them up on the Mac, and asked them to tell me what their intent was in making their work. I then ran it through the prepress workflow. None of them had their spot colors correct, and they actively mixed RGB, CMYK, and Spot versions of the same colors, and it showed how they would end up not matching if actually put onto product. (Consider this: Draw a large box, and then draw a a small circle in it. Make a CMYK blue, and assign it to the box. Then make an RGB blue color in the circle that visually matches the CMYK mix on screen. Send it to a commercial printer and have them make a professional proof of it. I can bet you will see the circle in the middle.) I then showed them how to fix these problems and prevent them. Most were gracious about it, but some were downright livid and thought I was trying to shame them. I was just trying to save their future careers.
The morass of swatch pallets you have needs to be collected and renamed. You can still have them accessible, and I can see where people will use them. But you need to track those colors as people click on them in that Document swatch palette, and never let people confuse between the swatch palettes and the color choosers.
Tinting should be more accessible and visible. Lets say you added PANTONE 286 C to your pallet, and you want to use the Fill tool to make a gradient with it. So, you have the 100% version already. To make a tint of it (and make sure that, unlike 98% of graphic designers out there with under 2 years experience, you end up turning most of your gradient to CMYK or RGB), make it so you can right-click and pop up the menu on the swatch and choose "Make Tint of this color..." Note that I did not say "Make Tint..." because this implies that it can be a tint of anything. (See where I am going with this? Professionals need control, and management, not just freedom.) You should then have the nice window you have for setting the tint, with an OK or Done button along with Cancel. Once that OK button is clicked, a new swatch should be added called "PANTONE 286 C 0%." AND IT SHOULD ALWAYS WORK. Right now you have to right click on a swatch, make a copy, and then right-click it, choose "Edit Fill..." and scroll all the way down to the bottom and choose "Tint." And god forbid if that color is a "Global" color, because as far as I can tell, you can't tint them. Frankly, this is sooooo CorelDraw. Nice cheap software for people to make pretty pictures at home for use on the church website and newsletter. Not for professionals who want to carefully create artwork that will color match anywhere.
Back to that gradient. The tip of the gradients should be then filled with the 100% and 0% versions of the swatch, and if the designer gets silly and chooses the white swatch (what is the color definition of that swatch anyway? K 0%? C 0 M 0 Y 0 K 0? R 255 G 255 G 255?), a warning should pop up telling them that "Mixing spot and process color will result in the gradient being converted to process using the document colorspace!" That will hopefully ward off that bad practice. AND ONE MORE THING: colors used in between those two swatches in that gradient should not show up in the Document palette as used swatches. I had that happen to me once and had no clue why.
Then you need to choose Separation Preview and look at your list of channels, turning them on and off to make sure you did it right. What Separation Preview you say? The one you didn't put into Designer and Publisher, but is in Illustrator and InDesign. That's what. Have it show overprinting by default without the ability to turn it off.
Next you need to save gradients into that Document swatch palette automatically too and have a means to locate where they are used and be able to edit them and reuse them. But that's another issue, and I am done for now. Just keep this in mind: your competition isn't Microsoft Publisher and CorelDraw. Its Adobe InDesign and Illustrator. Be different, but be better. People like me will pay you for it. See you when I have more time to give more feedback. You really have a good thing going; it just needs a lot of polish.