Full integration with native DAWs a'la Melodyne ARA would get us back to the Pro Tools TDM-style workflow, but even better I think for UAD would be creating a hardware console with the equivalent of a dozen cores, a center section with a touchscreen interface onto the selected plugin, plenty of i/o and expandable banks of 8 faders with assignable knobs. Having to navigate two separate DAWs effectively while tracking is just a nonstarter. To win me back I think the pricing has to go way down of course, but the thing that put it over the top for me was the fiddly Console app. But having sold everything and rebuilding in this day and age I've decided not to get back into UAD, the prices and instance limitations are simply too anachronistic, and with hardware clones from Warm, Golden Age and Klark Teknik offering decent real analog at true zero latency the idea of tracking through low latency plugins is no longer so appealing. I've been a huge proponent of UAD since the UAD-1 days, for many years running 14 cores with nearly all the plugs and an Apollo 16.
