When it comes to booking during the ownership booking window, either this short one for THV and BLT or the usual 11-month window, it's not about where you own it's about the points you use to make the reservation. Only home resort points can be used in the ownership booking window.
It's not enough to be an owner at SSR, you have to have enough SSR points to make the reservation. If you happen to own at other resorts as well, you can't use BCV points or OKW points or any other points, only SSR points will be accepted. Developer points are not SSR points so they will not be accepted within the ownership booking window.
And in fact, you don't even have to be an owner. You could have SSR points transferred to your account and use those to book THV on Sunday. It's about the points, not about being an owner.