H1b Consular Approved. Wish to transfer w/o activation.

Approved H1B (consular processing) from previous employer, but I’m currently on STEM OPT (valid until June 2026) and not working for that employer anymore. I’m now employed elsewhere and they’re willing to sponsor. Since I was already cap-counted, can my current employer file a cap-exempt H1B transfer with change of status from F-1 to H1B without me activating the old petition? Has anyone done this successfully without stamping first? Any risks I should be aware of?