One may want to switch to an SSB QSO while VaraC is running. If "Send beacons" is activated, VaRAc will send a beacon regardless of the frequency dialed in. This may be a wanted feature as is, regarding VaraC is polite and waits until the frequency is clear and minimal autosend interval is 15 min.
Nevertheless, it would be desirable to turn off sending beacons automatically, if the trx frequency does not match the frequency dialed in in VaraC. This can be achieved by checking if that frequencies match just before sending a beacon and turn off sending beacons if they don't. However, if the TRX frequency is periodically checked, this information could also be used to display the actual frequency (in red, if it does not match the user-specified frequency) which would be a great improvement, too.
In any case, it should be possible to manually enable beacons on a different frequency, which should result in sending beacons without auto-off.
VarAC allows freq read through from your rig. so when you change your VFO it will reflect on the VarAC screen. Most users user it. So there is no way for VarAC to determine if you moved your VFO for a VarAC QSO or SSB QSO.