3. I use VarAC native CAT interface to control rig and enabled"read freq. every 2 sec" too. Since I have also omnirig running on the same COM port shared, I have noticed that frequency in VarAC stop updating if Omnirig poll interval is set less than 2 seconds (I usually set it at 100ms) Only the freq polling is affected the frequency write to the rig is working fine. I have the possibility to use two physical com ports on the same CI-V bus but the behaviour is the same.
I think it would be useful an option flag to disable VarAC CAT polling, but enabling frequency update only listening the packets on the bus polled by omnirig or other software (e.g. Omnirig, FLrig both using polling to update freq/mode). By the way with frequency reading from bus also Icom CI-V transceive function could be used alone with VarAC embedd CAT interface