Damn, I thought I had sent the reply and it's been erased.

I'll keep it short, muscle memory for qwerty doesn't go away that easily, at least it didn't for me, but I'm able to type blindly in qwerty (just not touch typing). Still I think that something I can use in my laptop is very useful so I can keep the ergonomics on the go.

I don't have the exercises, it was just something someone told me to do, I'm sure whatever your doctor is telling you would be better.

For the split vs ortholinear I think split makes more difference, whenever I use a normal keyboard I feel this, but never had any pains related to it, it's just more comfortable.