That is something no one is going to answer unless you ask, especially sales people.
Cell over WiFi has really only caught on recently and not sure HughesNet even has a FAQ about it but a quick search will pull up many results about it not working well over satellite due to the high latency.
You didn't research it at all, especially if that important?
Very first one:
In fact, I think both the phone makers as well as the mobile carriers all have disclaimers about not recommending satellite internet for wifi calling.
Only problem with the Support Articles is you habe to be member/customer to view them I believe. So potential customer doesn't have access to them.
Never mind. Just tried it without being logged in. Just always goes to skylogin when signed in here so thought it was required, duh.