T:Slim X2 users - is there a way to add more insulin to cartridge?

Is there a way to add more insulin to a cartridge without changing the whole thing/having to refill the tubing?

Yep. Go through the normal change cartridge procedure, adding your insulin when it tells you to insert a new cartridge. Hit the unlock button and wait for it to register the cartridge. Then, pop the cartridge back out BEFORE hitting the fill tubing button. Don’t remove it completely, just move it free of the piston. You want to be ready to lock it back in place. After the pump thinks it has filled ten units, you can seat the cartridge back into it’s proper place. This is the only tricky part. You’ll get an error message if you put pressure on the piston. You have to time it right so that you snap the cartridge into position while the piston is retracted. You’ll be able to tell the right time by listening to the noises the piston makes.

In my experience, it never registers the full amount of insulin after doing this, but it will keep updating the amount and eventually does register it all.

Unfortunately, there’s no easy way to just skip the fill tubing process altogether. At least not yet. I think it might be coming in the next software update because a lot of people don’t change cartridges and infusion sets at the same time.