Use of Transaction Control Client extension to include or exclude employees in certain assignment an

I have the following business requirement. We are already using the standard transaction control to limit writing time on a specific project to certain employees. This is working fine.

We now have another project which people on Cost Center X, NOT assigned to Company A, or in Cost Center Z and assigned to Company B.

These costcenters have a high rate of people joining and leaving so I prefer not to use the standard transaction control by employee.

Can I use the Client Extension for this? With either flexfields at Project Level to activate the Client Extention (inclusive or exclusive) and then have a lookup of Value set which contains the allowed combinations of project, Org, CC?