My usual post which i don't think I've made here yet...
Since you are getting towards 2gb on file size, you should consider packing a bunch of the images into RPA files, archives. This will coupled with designating a secondary folder on android would let you avoid splitting the game into parts. By doing this, you (and android users) would not have to mess with the RPAs much, with apks still handling resources from updates since the last RPA.
Both of these are more or less standard practice for porters on f95 so you should be able to get the "how" from them as unfortunately i don't know myself.