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Bauerfiend is the best soft brace you can buy but its very expensive.
You said "affordable" which is a relative term, but the bauerfiend genutrain is about $75:
I have two, they are fantastic, just make sure you measure your leg exactly as they show on their website.
When you're extending your knees off axis, with weigh on them, you are putting pressure on the inner (or outer depending) parts of the joint that don't have the same "construction" as the rest of the joint. That pressure causes chips in the cartilage and stress on the ligaments due to the incorrect tracking of the patella (knee cap). So when you're in butterfly guard and lift, you're applying that stress to the joint. And, unfortunately, some people are just more susceptible to the damage than others.
Just to give you an idea as to where I am coming from. I have dislocated my right knee probably a dozen times, have had 3 surgeries (2R, 1L), and now have advanced osteoarthritis in both knees requiring Supartz injections annually.
I use this: Bauerfeind GenuTrain Knee Support
It gives me stability and compression while the gel pad acts as a bit of a knee pad while massaging the patellar region. It's pricey but it lets me roll.
I also highly recommend yoga.