Y-plan 2 zone system on combi (Rads + UFH) with Tado wireless starter kit + wired thermostat

Options

Thoughts on this?

System boiler with 1 zone heating being replaced by combi with 2 zone heating (all radiators on zone 1, but now separating UFH to zone 2)

The plumber wasn't familiar with Tado and its capabilities/limitations but having gone through it together we came up with the following modified diagram based on the Tado brochure's Y-plan but modified to use 2-zones which seems to work.

The combi replaces a system boiler in the same place. The UFH was on zone 1, but now utilises what had been the flow/return of the hot water and plumber thought that the Tado receiver was a 2-zone receiver but after reading the documentation when it's in combi mode the HW zone is disabled so from the components I'd already bought we've come up with this which seems to work.