it's an interesting can of worms you have opened up
The studies on mixed hetro couples showing infection rates as 1 in 900 is missleading
The infection rate could be due to treatment failure - poor adherence to drugs etc etc
One would also assume that these couples are engaging in full sexual encounters including the passing of fluids (ejaculation inside)
I'm not going to advocate what you are doing but there are some very conflicting reports out there that suggest various outcomes and statistics but without information that could explain them, I believe the details are left out to avoid individuals like you concluding certain things.
The first time this issue came to light was from some Swiss doctors who stated that
If you are on effective treatment for at least 6 months
If Your VL remains UD for that time
If You adhere to treatment
Then you cannot infect a sexual partner
Doctors Scientists experts around world were shocked by this statement and spent moths trying to argue that it was careless and sending the wrong message and have been trying to prove them wrong ever since
The one thing that stands out from the simplified criteria above is the 2nd one, how do you know that at the time of engaging in unprotected sex your viral load is UD, most of us have 3-6 month blood tests so for the time between your tests there is no sure way to know you are UD
I'll leave you with this thought, if you were HIV negative and dating an HIV positive partner and you were aware of their status and they satisfied the criteria from the swiss doctors but considering they were blood tested every 6 months - would you feel confident in having unprotected intercourse ?
How Many Roads Must A Man Walk Down Before He Admits Hes lost