My young (8 year old) child is starting to play around with writing music, and he's done a bit both on pencil and paper, and with a tablet app that is still writing on a staff, but takes some of the direct elements out (ie, you pick "eighth note" then it shows the 8 major notes on the two center octaves of your current key, you pick whichever note you want and it then places it on the staff, automatically doing all of the things like combining consecutive 8th notes into a brace and such). The app will also play the notes he writes for him whenever he presses play.
Much of what he's writing is well above the level he can actually play, in part because he's doing the standard kid thing of going to extremes ("here's an arpeggio made out of 64th notes at Allegro"), though he will play the parts he can manage to see if they sound good when he's doing it handwritten.
From a learning point of view, assuming this is mostly self taught (as he's a Suzuki Violin student, mid book 1, and hasn't officially learned written music yet), should I encourage handwritten over app-assisted, or app-assisted over handwritten, or just let him go with whatever he feels like? Disregarding any concerns over screen time (which are there, and separate, but I'll manage that how we do all the rest of his screen time). Mostly concerned with habits (if either method is likely to teach him habits that will hurt, or help, his ability to learn if he keeps this up), and partially wondering if the ability to have the app play for him is going to benefit in the long run (as it means he can more readily get feedback on his writing) or hurt (as it means he doesn't pull out the violin and test things).