As I understand "double-jointed" it is about loose joints, which can be made to make movements beyond the normal (I am not a native English speaker, so I may be way of by now).
With the above understanding I can say, that I myself am double jointed. That caused big problems for me as a kid, because my ankles would collapse very often. I learned a bit about how to avoid the worst consequences of falling, which is still a helpful lesson.
I had to re-teach myself how top walk, when I was in my mid-twenties, but the wear on the large joints has still been quite noticeable.
On that background I would say, that the trick in avoiding fingers to collapse is about never letting them work from a straight "home" position. Always arch them ever so slightly and keep the arch during the finger movement. That puts the work on tendons and muscles, but takes the stress away from the joint capsule (if that is the proper term?).
From a tubaistic point of view I wonder a bit about the cited 1+3 fingering being a major problem. On a 4 valve compensating instrument like the 983 the 1+3 combination should only be applied in rare situations: a whole tone trill between F and G or between Bb and C.
In connection with the 4th valve 1+3 also are to be used for the low F.
Actually it is not a matter of compensating, but about instruments with 4 valves: the 1+3 fingering should just about never be used. The in-tune solution is to use the 4th finger.
That on the other hand may create other problems for your pinkie. I know about that from my 5 instruments with 4-in-line valves, especially those with pistons. (The 3+1 set-up is by far superior from an ergonomic point of view)
Fast moving passages tend not to cause the most problems, as there is a lot of motoric tension and release. However long notes can be bad.
The dirty and non-scholar solution is to substitute stressed fingers with the less stressed ones. The thumb comes in handy here as does the edge of the hand. If your arms are long enough, you even can use a finger from the left hand for long notes.
Being double jointed has its problems. To illustrate the degree of them:
One of the few regrets I will take with me in my grave is, that I didn't kill the orthopedist who for the mere fun of if dislocated one of my shoulders to show a colleague how deep he could press his thumb down in the joint. It took months to recover from that. Had it been the right shoulder, I hadn't been able to play the trombone, and then murder had happened.
Klaus