Advice needed urgently

I would really appreciate any advice that anyone has here, as huge panic has set in.

My husband sent in an HSMP application in April. At the time, he was in the UK on a student visa. He left his postgrad program, after checking repeatedly with the HSMP team and with Croyden to make sure that he was eligible and able to switch visas.

Well as you all know, HSMP processing is taking months and months and mid-stream for us, the HO changed the rules on in-country visa-switching. As of Oct 1, in-country switching will be restricted and will no longer be allowed for those on student visas who did not graduate from their program. I've been watching for any news to try to anticipate when my hubby's HSMP might be processed and I knew it would be close for getting the FLR into HO before Oct 1.

Well... this morning, my husband got a registered letter from HSMP asking for further evidence. It would take us a few weeks to get that info and then take them time to get it processed. So, Oct 1 will be long past by then.

The crucial question is if there is any way that we can leave the UK and apply for EC from our home country if his HSMP is eventually approved, when he applied in-country?

We have a remote possibility that a WP might be able to be processed fairly quickly, but then we'd likely miss the Oct 1 changeover for in-country visa switches anyway. Does anyone know how difficult it might be to leave the country with a student visa, then reapply for EC with a work permit? We would continue to try to get the HSMP approved in that case.

HELP!!!