This 5335 KHz frequency built into VarAC is a problem for us US amateurs. Let's face it: people who are installing and using what is a new program to them make certain assumptions, including any channel frequencies provided by the program being legit for their use. Especially since the 60m band amateur allocation is so relatively new here in the US, and the operation of ham radios in those five 2.8KHz wide bandwidth channels require some level of technical understanding of suppressed carrier USB versus digital mode center frequency allocation, one cannot reasonably expect operators here to figure this stuff out on their own and adjust whatever software file to correct things (imagine the average commercial truck driver here fiddling with software coding). 5335 is NOT legit, and using it will invite at least the scrutiny of the US Dept Homeland Security and its CISA agency, let alone the many federal and military users who are the FCC designated PRIMARY uses of the 60m band here in the US. Worse, hams having their licenses suspended and fined, worse yet the eventual removal of amateur radio as secondary users of the 60m band if the problem becomes untenable for primary user allocation. Beaconing (aka Sounding), extended chatting, and FT8 contesting are examples of US amateur use of the 5 designated amateur frequencies in the 60m band that potentially may invite problems even if they are on the correct frequencies. Using 60m band frequencies, such as 5335, that are reserved for federal use is like waving the red cape in the face of the bull. Since the primary use of the 60m band is for emergency communications (as defined by the FCC), then us secondary users are safest also using it for emergency communications applications. I'm one that views VarAC as useful for emcomm (as opposed to FT8 for example). As to which of the five amateur 60m frequencies should be used: that depends upon HOW VarAC operates regarding tuning the CAT controlled radio. IF VarAC is coded to place the VARA center frequency as what appears in the list of channel choices in the app, then the appropriate FCC specified digital/CW frequency should be listed, which happens to be exactly 1.5KHz above the FCC specified suppressed USB carrier frequency when using voice. an example is channel 1: 5332 KHz. IF VarAC is coded to tune the CAT-controlled radio to the USB suppressed carrier frequency, then it must have VARA place its center frequency of its modulation 1.5KHz above that; for example, tune the radio to 5330.5 KHz, and then modulate to place the VARA center carrier at 5332 KHz. There are five such channels to choose from, but best to choose one that can be a standard used by everyone, at least everyone here in the US who are using the software. IF such frequencies vary among bands among different national telecomm authorities, perhaps separate codeplugs and be downloaded/selected/installed to help prevent hams from getting them and others into trouble. 60m band is NOT "hardly used" by amateurs. Perhaps hardly used in the EU, but different story here in the US, especially when it comes to ALE (a great use of that band BTW).