At our bank, if the application is truly a preapproval, we would use the date on the 123 TBD app as the HMDA application date. If it is a prequal app we use the date on the application with the property address since that is when the application became a HMDA app.
We have a preapproval program and a prequal program. So this got a little hairy for us a few years ago.
I think this part of the commentary may help you.
If the financial institution chooses to report the date shown on the application form and the institution retains multiple versions of the application form, the institution reports the date shown on the first application form satisfying the application definition provided under 1003.2(b)