Hey, y'all. Just wanted to share this with you. I've got my UFSmk2 running at the full 6ml capacity with a 510 atty. Here's how I did it.
Step #1: Find an old carto and cut about 1/4" off the top of it
Step #2: Find a ballpoint pen with a rubber grip and cut about 1/4" off of it. Something like this:
Step #3: Slide the rubber piece halfway over the atty, then slide the carto bit in and join them together. You've extended your atty and can now put all the UFS bits on for a 6ml tank.
Hope this helps some of you out!
Step #1: Find an old carto and cut about 1/4" off the top of it
Step #2: Find a ballpoint pen with a rubber grip and cut about 1/4" off of it. Something like this:

Step #3: Slide the rubber piece halfway over the atty, then slide the carto bit in and join them together. You've extended your atty and can now put all the UFS bits on for a 6ml tank.
Hope this helps some of you out!