Hey, thanks!
I tried to "trim" the tileset to include as many different tiles I could, there's some tiles that have horizontal/vertical flipped versions or rotations included for convenience (some diagonals, "border" tiles etc), but yeah it's optimized for a workflow where you quickly pick foreground/background color and a tile and just place them on the canvas; I mostly use Playscii for this as it's the most convenient for me.
I just released Microbe-2, which is sort of a MRMOTEXT-lite, using 6x6 tiles instead of 8x8, but using the same "shapes and details" philosophy. It's free, go take a look!