I've already been awarded, in total, an amount less than $20K in CY2023, does that mean I can only request up to $20K in reimbursement in total in CY2023?

Yes. For example: If you’ve already been awarded $15k in calendar year 2023, then your company’s yearly threshold is now $20K, and your company may only request up to $5K in additional Express applications for the remainder of this year.