Hi!
There's a user ( @TheNoobPolice) that I think that explains it very well. The main takeaway that I've got from him (I might be wrong interpreting his view) is that we all have a level of aim skill and we improve it overtime, regardless of the sensitivity we choose. The thing is that when we get used to a certain sensitivity, our aim with that sensitivity is basically the reflection of our own level of aim skill (in contrast, when you change your sensitivity, there's an adaptation period until you reach your aim skill level again -note that in this process you might still improve that base level-). This goes to say that you should probably avoid being in that adaptation phase and your "perfect" sensitivity is the one that you are used to the most.
Now, if you want to change your sensitivity (and then stick to it), I've seen that it's usually recommended to go with a 360º distance ranging from 20 to 40cm/360º, give or take. It doesn't really matter which one you choose within that range as long as you feel comfortable and stay consistent, as you'll get to your actual aim skill level after adapting to it.
Another aspect to take into account is desktop and ADS scaling. I'd suggest to go through all the games that you usually play, then see which one has the worst sensitivity settings and adapt to that one; e.g. I love playing Destiny 2 but it has a very limited FOV and hipfire sensitivity sliders, and the ADS scaling doesn't allow to set MDV 0%, so I decided to match everything to 100.8 HFOV (the maximum FOV available in the game) and MDH 100% (which is the only option that actually makes sense for me in that game). When you've done that, look for an in-game value that gives you a sensitivity that's between 20 and 40cm/360º (more or less) and convert from that to everything else. Alternatively, you can select a desktop sensitivity (DPI) that gives you your desired 360º distance when converted from desktop to game, so that you always stay consistent.
I'd also like to point out that you can also adapt to any MDV/MDH % if you use different zoom levels in aim trainers, so, although MDV 0% is objectively the most reliable conversion method, if your base game doesn't support it, it's probably not that big of a deal, as long as it supports at least one logical ADS scaling method.
This might be what you need, but there's a lot of possibilities, so maybe someone else can give you an advice that fits you better.