Movies easily use up to 4/8k UDIM tiles. So either you have to use higher res textures or split your UV's over more UDIMs. As far as I know there's only one software package that enables you to continuously texture/paint over multiple UDIMs, and that's Mari 3D. Substance painter supports UDIM tile sets but doesn't allow…
Paint or generate it in whatever program you want any way you like. This is an unanswerable question given how vague it is. You've made a lot of threads recently asking related questions that could be answered by learning more about the processes behind making last or current gen art. Much of the information you could find…
Or like Substance Painter but working in 2d space with pixel snap precision . Something simple like 2x2 ? Vector style maybe including vector curves to scatter small things along. With color range selection ? Something for quickly compositing materials from already existing pieces , not even any 3d preview is necessary but…