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.