As a professional graphic designer who seeks to replace Photoshop and Illustrator by Photo and Designer, I would have these humble suggestions what to add to Affinity Photo for iPad:
Possibility to switch off spellcheck in global settings. It is annoying to switch it off in the Text Studio every time after opening a file.
Select all visible pixels of a layer by one click.
Text on a path (so we can make a curved text).
Paint a pen stroke with a selected brush.
More filters (like image to sketch etc.).
I know some of these features were allready rejected to add by the developer because they have said, Affinity Photo is just for editing photos and we should use Affinity Designer for design. Dear developer, please, reconsider this. I have, and I believe many others these days, been using Affinity Photo as a replacement for Photoshop (and Designer as a replacement for Illustrator). If we want to make a design primarily based on raster graphic, or prefer this way of work more, we go to Photo and make the design there. If we want to make something typically vector, like logos, we go to Designer. You do not need to be afraid that we will not use Designer because we would make everything in Photo. We just need a raster focused tool with also vector tools (Photo) and vector focused tool with raster tools (Designer). In other words, replace Photoshop and Illustrator, that is it. If you want to win us, please, reconsider viewing Affinity Photo as just a better photo editing tool.
Also please consider, that we are already using some of these features in Affinity photo by means of macros. There is a famous set called "Mud's Macros v3" including e.g. Slection from Layer, Pencil Sketch filter and Text on a Curve.
Hopefully this will be understood by the developers. I should also say that you did already a great job!