Is it possible to add smaller versions of the laboratories?

It should be possible, but I don't know how useful that would be; you generally want to have larger labs to insert all the new science packs into the machine. It might also look incredibly messy with all of the science packs in the alt mode overlay, especially for a 1x1 entity. I suppose I can look into it though, but no guarantees

for drones it doesn't matter)

If you had a 1x1 lab, you would be limited to 4 sides, AKA 4 inserters being able to insert science into the machine, even if they are fed by bots.

If you have any amount of additional planet mods and high amount of speed on those labs, you could easily be throttled by the inability to physically insert science into the lab fast enough (though you could fit more labs in the same space, they wouldn't all be running at 100%).

Bent manipulators load quickly.