Hi Darryl,
1 - Sorry for confusing you, the Power Factor P.F. is just the notation of Cosinus Phi (angle between Amp an Volt sinus) with the Harmonics Distortion (THd) correction on the A/V sinus-shapes.
In your case, the SE inverter is behind the MP2 inverter when charging the batteries, the influence of P.F. control is neglectible because the MP2 is controling its own P.F. setpoint as per Grid Code EN50549-1:2019
If you want the MP2 to correct the P.F. as in function of voltage rise, you have to change this setting, but password is needed.
2 - In your case, when you want to disconnect the mains from the MP2, based on a high volt detection, the SE inverter is not acting on the Hz-slope that is set in the MP2 Assistant configuration: *ESS (Energy Storage System) The SE will remain conected for a minute or so and than stops on Hz-high alarm, waits for a few minutes and starts this all over again, and again, and…
SolarEdge “Alternative Power Source mode” (APS)
As a work around you have to set the SE configuration to the same Hz/Power slope and add a voltfree contact, controled by K1 from your MP2 This contact has to act when you disconect the mains from the MP2. (to keep it failsafe, i used the relais action inverted, but you can use it as you want)
important info on potential diference between SE input and K1 “relais”driver on the MP2