I made an account here just to boost this. It's legitimately the only thing stopping me from using affinity as my main drawing app. I love it but artists use the undo function a LOT ... we need a fast way of doing it that doesn't involve pressing a button on the UI.
On desktop applications, there's hotkeys. The ipad doesn't have this capability.
Please add the two finger tap for undo, and three fingers for redo. It's standard for most drawing apps :)
Also, the Affinity team really should start marketing a bit towards artists...! I always skimmed past the app on the store thinking it only had photo-editing features, but when I found out it had a full on brush engine, it was an immediate purchase. There's no other app on the store that is comparable to a heavy duty desktop program like Photoshop, while ALSO having a really great, user-friendly UI.