That's not really my experience many are quite savvy when it comes to unprotected sex. Saying that I am sure quite a few will BB just like the pro$$ies who think its abhorrent then offer it under the radar for more cash

I think it really depends, SBs are not a homogeneous group. They’re not all WGs and not all of them have an escort mindset, it’s a real spectrum and many of the girls do see it as a way to spend a bit of time with an (older) wealthier man, that may treat them bette, take them nice places and maybe get a bit of spending money on the side.
The more pro/semi-pro serial SBs are far less likely to have unprotected sex because they’re basically WGs. Some may offer BB for more money.
The more regular broke girl/student who is new to SA is far more likely to have unprotected sex not because they “offer BB” but because they’re not WGs and more likely to replicate their normal dating habits if they are comfortable with you. They don’t ask for more money as they’re not seeing it as a service offering. The bigger concern for them can be pregnancy rather than STIs.
But as someone else said earlier in the thread ...... it’s more important that we wear a condom if SBs having unprotected sex with other partners is a major concern for us.