Two 1-1/2" vents serving where a 2" vent is required

[Gods]

I'm venting a bathroom group (sink, toilet, bath/shower) and the rough in location ended up placed directly below a truss, which means I can't take the 2" vent directly up and out. I'm working with a 2x4 stud wall and need to bore through several and make a turn to avoid the truss. Is it code-compliant to run two 1-1/2" vents instead of a single 2"? or is a 2-1/2" bore acceptable in a 2x4? These are non-load bearing walls.

Based on DFU counts, a single 1-1/2" vent should suffice, but I understand code requires a 2" vent for toilets regardless of DFU (toilet is roughed in with 4" pipe).

Thanks!