basing the next generation of FTL after Warp drive on the Borg's Transwarp Hub is a very flawed idea.
First of all, you have no network of transwarp apertures/conduits in Federation control in Federation space. Any pre-existing ones would be of Borg design.
Unless you have eradicated the Borg in your timeline, then good on you. If you haven't... then you will need to deal with the obvious repurcussions of Starfleet using Borg Transwarp corridors. We're talking a Starfleet vessel uses a conduit to get from the Alpha to the Beta quadrant, within minutes theres a Cube on an intercept course and within sensor range.
If Starfleet in your unverse wants to begin construction of their own Transwarp Network, then you're looking at decades of construction time.
Yes, Voyager returned to Federation space with specs on a Transwarp coil, but they also returned with specs on a QSS. And for all it's faults, the QSS is much safer in the long run.
I recently came up with a future of trek idea where the Federation by 2440 has connected all major planets within Federation space with Transwarp conduits. Due to the tactical advantage the Transwarp conduits give the Federation it brought about tensions with the other powers even the Klingon Empire. To ease fears and tensions and prevent war the Federation agreed to sign a treaty preventing the use of Transwarp conduits outside of Federation territory.