I have a xMagic at P0 on my right hand (the webbing) and a flex secure on my left forearm. The xMagic, I believe, is slightly larger than the xSIID. I didn’t use lidocaine for that install (I did for the flex since it’s much larger but I’m not sure how much it really helped).
Basically the install is ~30 seconds of a fairly bad burning sensation. Not unbarable or enough to need pain managment but you know, I won’t have liked it to last much longer. For the next 4-6 hours after the install it will be kinda sore, but not terrible. After that I didn’t really find it to be painful or inhibit my ability to use my hand. That said you’ll want to keep the area clean and let the site heal, so don’t do anything crazy.
It will take around a week for the scab to start looking good, and ~2 weeks for the swelling to go down, and you’ll probably find a bad bruise around the area.
The glass injectables are definitely known to migrate a little ways from the install area, so the less you move your hand, probably the better. Some people try to minimize their movement until it heals, others try to use external bracing to keep the implant from moving while it heals, while others are of the opinion that some movement is fine and the implant will naturally settle to a location that doesnt experience too much movement.
I guess my two cents would be if you’re concerned about it, aim for a Friday install after work, take it easy the next two days, and you’ll be typing fine come monday.
Hopefully I answered your question 
Tldr. Pain isn’t really bad enough during the install to be a concern. Little to no pain pretty much immediately after. Overall not too bad and worth it!