v_kyr

See my above post add-on and also look here.

You probably will then need super user (su aka root) privileges to to so. As root (su) you should be able to change permissions on the system! Take also a look here and to similar explanations!

I use Designer on a pretty old (outdated, no Metal mode) iMac running El Capitan with no problems so far. So it should run pretty fine on your much more powerful and more modern iMac hardware version. - Download the Affinity Designer MacOS tryout version first, give it a good test run and you will see for yourself.

Did you also tried the older Google NIK Collection version (2012, see the Email demand), does it behave the same?

Well since Affinity Photo is first at all a bitmap editing/modification program, you can pretty much still do the same in it. Meaning opening some tiff image, selecting some colored areas of that and then replacing the colors with youre own ones. However, if you mean instead more to trace/vectorize a tiff image inside Affinity Designer instead, then there is no build in autotrace function in that one. You would have to trace (redraw) bezier curves by hand or use some external tracing app (vectorizer) first and then modify (color) the vectorized results in ADesigner appropriate to your likings.

You can try to use the NIK Collection in standalone mode (see here) and then open/load the NIK modified image in APh afterwards. - Further if you use the older NIK Collection version (2012), then the plugin-interface probably doesn't behave like that, since DxO for sure in the meantime (for the 2018 version) made changes here for nowadays PS/LR version interoperations. So you may want to try how it behaves instead with the older NIK Collection version.

Depends on the version you're using, see here on their site a link to the still available free download version. - See also NIK Collection 2012.

See Convert PDFs to Word and Co. there. You can also give such online converter tools a try.

Well if it doesn't hurt in your case, if the watermark size might be distorted and oddly resized during macro autoplacing processing, since placing/resizing is not dynamically (re)calculated for different image sizes, then this might be the way for you to go. Give it a try.

Leave out the saving (export process) out of the macro and instead apply the recorded macro to the APh batch processing feature, which will perform the export (saving) for you then. Further note that automatically resizing/placing watermarks in images etc. is still very fuzzy at the moment in APh.

Well you have to pick up the Adobe Photoshop plugin API and take a tour de force with that, meaning studying, trying out and learning how to make use parts of that API for intercommunication. So having some knowledge about the general structure and workings of Photoshop Plugins is very essiential here. - However there aren't that much docus and tutorials etc. about that around, so you will also need a good portion of passion to find related informations. Programming Photoshop Plugins How to Create a Photoshop Plug-In Plugin Creation Tools And since the APhoto plugin interface isn't documented and there aren't any educational samples available, you will have to use the TRY and ERROR approach here for this!

I'm not RC-R, but I get the following for OSX here ...

On a Mac (OSX) performing just a "Save as" without altering the opened file in any other way doesn't change it's size for me ...

Congrats to the community here, since first of all your votings did it !!!

Note further that there are two ways to load macros ... *.afmacros (macros files with a plural s at the end) are loaded via the top menu View -> Studio -> Library panel and it's associated little hamburger menu *.afmacro (singular macro files with no s at the end) are loaded instead via the top menu View -> Studio -> Macro panel and it's associated little hamburger menu