All seems to work well. Just a couple of small things to report so far. I run a TR590SG in one configuration and an IC-9700 in a second configuration. Running V2.4.0-rc1, Windows 10, 64 bit.
1. In the TS590SG configuration on 50.275, Q65-30A, the Tx6 check box next to the Call 1st is gray and can not be checked. All else seems to work just fine.
2. When I change configurations to the IC-9700 and go to 144.170 Q65-30A, the Tx6 check box is no longer gray. However, my CQ K1YOW FN42 inside of Tx6 now reads: @1000 (TUNE). If I put in CQ K1YOW FN42, all is OK for the CQ. I then switched back to the TS590SG and Tx6 still has my call. So just to see, I switched again to the IC-9700 configuration, and Tx6 again showed @1000 (TUNE) instead of CQ K1YOW FN42.
All in all, I have V2.4.0-rc1 working fine so far and it coexists just fine with fldigi as well using W10 64 bits.
73, Joe, K1YOW