I would be surpised if the quest 3 used anything above 9V because that is what their wall adapter has. Also, I think the highest amps you can get for 9V is 3A (27W), but that was from a quick google search. There is another thread floating around where someone measured the power draw of the headset under different conditions, and I don't recall it even getting to 27W. I'll add a link if I can find it.
The battery that came with my bobovr m3 is actually a quest 2 battery and only delivers 5V at 2.6A (acording to the label on the back). I find that the quest 3 is at about 88% when the BOBOVR battery is depleted.
The only battery I've tried that was actually able to charge the headset while playing was large ROMOSS Sense 8+ that has 9V/2A. The first time I used it (when I first got the headset), the USB connector got quite warm. Since then it hasn't, so I'm wondering if firmware changes may have changed things since I first started testing. Honestly, even the 5V/2.6A battery on the BOBOVR is good enough for me, and its magnetic and very easy to hot swap (although I personally only have 1 battery for it). Note I have seen posts about people saying their BOBOVR makes a buzzing noise. You may want to look into that. I have not experienced it.
Can a 3rd party battery hurt the device? Who knows? That is a risk anyone who plugs in a 3rd party device has to take. I can tell you that I used 3rd party batteries for years on the quest 2, and have tried 5 different batteries on the quest 3. I can't tell you there is no risk, just that it is a risk that I personally chose to accept.
EDIT:
https://communityforums.atmeta.com/t5/Talk-VR/Quest-3-Power-Usage-Tests-and-Approximate-Battery-Life/m-p/1094433