My DD has hypermobility, too. I'm not sure about degrees, but perhaps hers was not so bad as she crawled and now toddles normally (if belatedly).
I can't tell you about later years as we're only a little bit ahead of you.
One thing I can tell you is that our physio said that encouraging 'proper' sitting was helpful to develop the hip/legs. I wear her a lot and the wraps make a really supportive seat to encourage optimal positioning. The structured carriers are not so good as her hips spread out too wide. I don't know if being worn a lot has helped her at all (no way to go back and not do it to compare ). I wonder if using the ergo a lot when she was younger may have made things worse
I'm sorry you've been through a lot to get help! Hopefully now you're on track