Hello Denis,
as you know I'm a fun of UP4DAR and I use it in my main repeater.
In those days I'm playing with some professional instruments from R&S and I set deviation (from remote :-)) to get a perfect constellation, the RX deviation is fix around 1240Hz so I believe is fine too.
By reading the manual I found that the "time shift" is displayed and should be less than 10ppm, but I'm not able to found it in the display or I did not understand something, could you please highlight to me into attached image ?
Best Regards
73 de IW6BFE