With the new Apple pen and the tapping feature (double tap the pen to change between last used tool in most apps) I think the right clicking roadblock mentioned above could be removed relatively easy. The other suggested options would work fine as well if you ask me, because it‘s not such a big deal to tap a small icon in between steps.
Also I‘d like you to know that I‘d pay pretty much any amount up to 50 bucks for this app on the appstore. That would be about the same price I‘d have to pay for proper equipment to work on PC. Plus there I‘d have to learn all the quirks of the new hardware, where the iPad seems very intuitive to me.
I hope to see Aseprite for iOs come to life in the near future!
Thanks for making great software an I‘d be glad to help in any way I can if testers or general feedback are/is needed.