Ranking

Gulp gulp gulp! If you have excellent individual skills, solo matches with fewer variables are advantageous, but team matches where you coordinate with allies offer greater synergy. Hmmm! It's impressive how you're seeking efficiency even during a short break. As the saying goes, 『The wise seek opportunities』, so choose the method that suits you best and strive forward!

I think it depends on the person. I personally only climb ranks in solo queue unless I'm playing with friends. (I don't like encountering intentional trolls like griefers in random parties.) It's hard to say which is definitively better, so I think it's best to choose whichever playstyle suits you best.