@Ja***
you got your extension based on employment some how without a TM30, and you've been doing 90 day reporting without having filed one,
I don't think you're actually going to need one.
When you go to the immigration office to cancel your current extension based on employment apply for the covid extension right after.
OR
As you said, go and apply for the TM30 Monday before you need to cancel your extension or apply for a covid extension just in case you DO need it