Yes, right now I would say staying on colchicine makes sense because of your symptoms. Obviously if these symptoms persist an extraordinarily long time you will have to change strategy. You may develop a better sense of what symptoms warrant colchicine over time but I think that right now is a good time to be cautious.
Indometacin would be an alternative if you tolerate it better than colchicine (I tolerate colchicine better but we’re all different).
I doubt colchicine would do much more than indometacin to prevent crystals from forming. The main difference I think is that a given dose of colchicine remains in the body longer and that taking a small amount every day is generally less dangerous than to take delayed-release indometacin every day. So it makes sense to use colchicine as a preventative. But taking a lot of colchicine (that is, more than you take) every day isn’t recommended and even a small amount could end up causing serious side effects over time. The problem is basically that if your body can live with the amount of colchicine you’re taking, it can also contribute to crystal formation.
Taking “only” 40mg was irresponsible. That was quite a strong dose and not a reasonable initial dose for somebody who has already had trouble with side effects. Hopefully you learned the right lesson, which is to exercise due diligence with drugs and not to ignore reasonable warnings. The right lesson was certainly not to avoid all drugs which lower UA regardless of how they work.
And being afraid of drugs is obviously no reason to avoid getting preliminary tests which would if nothing else give you clues about improving your diet. You could of course improve your diet without getting tests but why do it blind?
Finding a good doctor willing to support you may take you quite some time to begin with so you might as well start now. The day you develop serious problem will be too late. It may be different in your your country but patients with special problems often find it difficult to secure the support of a doctor willing to pursue all the options recommended by the medical guidelines (nevermind non-conventional options) and not just the most common therapies.