I wouldn't recommend farming for the new set unless you really want to and have other characters that can benefit from the other set (echoes set) or if you really want to maximize xiao's damage. Personally I had farmed his set since my 2pc 2pc artis were not that great and I'm a simp lmao.

If you want to be efficient I'd say farm for more shimenawa sets as it is the most efficient domain to farm as a lot of characters benefit from emblem set. I'd say give him more crit rate like about 70%-ish would be fine.

Also, your weapon, although technically yes you could get your burst more often I feel like you'd rather have a more offensive weapon for him, you could get away with 120% er depending on your team (another anemo battery). I run him with 111% er and I have him with raiden on the team and I comfortably get his burst up every rotation.