30c tubeless tyres didn't stop the issue on bcm, but have tweaked handlebar position since then, which hopefully means less weight on hands. I should probably buy some new mitts though.
I used to be able to ride gloveless with no issues, so a bit annoying that it's become a problem.
I haven't had a problem with numb hands since adopting:
Gel under bar tape
Gel padded mitts
25c tyres (30c on the rear)
I have aerobars fitted for LEL so hopefully that'll help, too.