What legal hoops, dance moves, or traps are in store to take a rifle barrel down to 16"< then adding a perm welded muzzle device to bring it back up to legal length?
I hear about the AR guys doing it all the time with a 14.5" BBL/upper but those can be bought and/or seperated rather easily.

Even with removing the BBL from the action the "intent" clause is nipping at the heels, correct?

How do others get around this? I know ive heard of plenty of Mini owners having this done in one fashion or another.

There is no "intent" ever.  You can avoid "constructive possession" by having a nice stripped lower or AR pistol around so there's a legal way for you to use that upper you shorten, while it's still short.  Alternatively, you can have a smith do the work, so it's never in your possession when it's under 16".

Might have to go the smitty route as this isnt for an AR- its a bolt gun.

to be done properly the barrel needs to be removed from the action...........thus no issue of an SBR......it is just a barrel......once it is out of the action.....set up in the lathe....chop it, crown it, thread it, and mount the brake/muzzle device and then pin and weld......then reinstall in the action and check headspace.

Or send it to your local gunsmith and save the take out, re install, and head space. My lathe is large enough to do 97% of the barreled receivers out there. The only time I take a bbl out is on an AK variant due to receiver size and that most AK barrels are not bore concentric/ parallel outer surface to bore.

As long as the barrel in not in the receiver there is no issue with it. for a pistol there in no limit for a rifle unless you have a SBR stamp and it's legal to own in your state it needs to be 16 + inches with the muzzle device pined and welded. The proper way to determine if it's legal it to close the bolt and insert a rod or dowel with a mark at 16" to the bolt face and make sure that the mark is below the end weather it be the barrel or permanently attached muzzle device, and the definition of permanently is if forced off the threads well be unusable to attach another muzzle attachment also it needs to be welded in three places or blind pined and welded over the pin.