Question about end game grind spot for BMs

Hi! im at lvl 153 with my BM and i wonder what are the best places to grind. 7f? 5-6? Templ of time?
I saw many ppl farming in 7f but always accompanied with someone. Is a duo really necessary? is this more efficient? if its, what are the best duos, do i need someone to agroo the mobs for me? what is the most efficient way?

And how about 5-6f? it doesnt look a good place to grind taking into account the map design.
Maybe with someone splitting the map horizontally?

I also don't know anything about Temple of time spots, is there any good place to farm there?

i have a Hs mule and i finished my washing too, please pass me your wisdom ty in advance!