Just my personal experience has been with training for a number of days per week.
1x a week - yeah looking back this was terrible, not nearly enough to progress, you go one week and literally forget everything by the next session, its very hard to make progress imo
2x a week - Your average hobbyist - clean, good time for recovering, you can start making progress properly, and yeah as my coach said it’s the bare minimum to have steady progress. Con is there’s too much time be tween each session. From this point on please use tape and a mouthguard.
3x a week - pretty good actually, id say ideal, this is where I started really picking the pace up in terms of progress and understanding I think. Quite a sweet spot for recovering and progress
4x a week - what I’m currently doing, even faster learning, very low time between sessions, max you’ll have a two day gap between sessions. This is what works for me even in my very busy schedule. Main con being time taken up, and your body might hurt a little more often, like after a hard day you’ll have kind of a dull ache lol.
6x a week - I’ll just skip 5 cause same thing basicllay, but i do this during the holiday periods (yes I’m a very sad individual) cause I want to make good use of my time. Yes you ache, am I having fun though and learning very quickly and contributing even more to my next promotion? ye I am.
Well that was my very amateurish experience with each number of days training per week. In actually my exactly one year of doing Bjj. Myabe the higher belts on this sub may start flaming me and telling me I haven’t got a clue what I’m talking about lol