as posted, on Desktop (affinity Designer/Photo / Photoshop, etc) this quickly and PERFECTLY selects a pixel layer. think 'marching ants' - not a rectangular transform selection. this works especially well for very fine lines or rasterized color gradients, etc. it honors slight variations in pixel opacity. however there is no way to do this on the iPad version of Designer or Photo, at least i cannot find it.
every site i ask this question on seems to think the selection tools suffice (flood, smart, etc), but i've found that's not the case. adjusting tolerance endlessly still doesn't give me a perfect selection of pixels. on Desktop apps,i like to use a selection like this and use it to paint black or white in previously created layer masks, or even use the selection to 'punch out' that shape into a new mask. but the selection tools available in the toolbar make it look harsh or jagged, especially over high contrast backgrounds.
please advise, am i missing something or is the functionality not included on iPad? this doesn't work with a BT keyboard either, as Cmd+Tap Layer does nothing.
thanks!