The orange/blue virtual open houses are now up. They include some pretty detailed schematic pdfs.
https://capmetro.org/get-involved
Edit/Add: some potentially interesting notes from the orange line presentation.
" Slaughter Station would likely be near the Ralph Ablenedo Drive and would include a park-and-ride connected to I-35. This connection would provide convenient access for those coming from the south on I-35. "
"It is critical that the guideway line up to cross over I35 to hit Center Ridge Drive on the other side because TxDOT is proposing to connect the managed lanes of I35 to the Tech Ridge Park and Ride"
They don't really go into details as to what form "connected to I35" would take on the south end, whether it would be new ramps/T-ramps. But it does start to seem likely that the location there (short of Slaughter) is at least partially due to I35 connectivity.
If they were to have direct connections on both ends, you could eventually see buses from Round Rock/San Marcos traveling in carpool lanes and transferring directly to the Orange line. Would have been better with full tolled managed lanes and 10-15 minute frequency highway BRT (like as was originally proposed for I35), but maybe in a few more decades.