Ah yes OK. A completely new visa for a different reason. Yes OK that make sense. Ellie said "a new visa with an extension before it expires?".....I think she means....just a completely new visa for entry. No relation to the old one. There would be no extension of anything involved. Got it.
A multi entry visa is pretty much useless at the moment with 14 day quarantine. He needs to change it from a visa to an extension of stay by showing 400k THB in a Thai bank account for 2 months. The 90 day report is for those who already have a year long extension of stay, and have to report to immigration every 90 days.