That sounds pretty awkward for typing more than a few sentences. Do you have something to angle the keyboard somewhat?
In my experience, I've found a MS Surface and a gooseneck ipad holder is a lightweight ideal laydown desk. I clamp the gooseneck a few feet above me in bed and I can lay perfectly flat and have access to a full PC.
It also can be disassembled and stored in moments.
Could you please point me to your choice of stickers, or mention the brand? I desperately need some bumps on the current keyboard and thought of messing with glue and plastic, but it hasn't occurred to me that someone already made a finished solution for that. From searching, I now see a bunch of related stuff, like braille and such, so it would help to narrow it down to more suitable products.
Laying down and typing is at a weird angle so you can't quickly check that your fingers are aligned right. It is just easier to have a tactile anchor at the far end of the keyboard, particularly when typing fast.
It doesn't take much, just the smallest sticker can change the feel of a key.