Advice re timing of application

Plan to emigrate to UK at end of the year. The timing of husband's HSMP application becomes somewhat tricky:
1) If we're not planning the move before the end of the year, we should likely not submit an application until late summer?
2) Or, do we submit under the current plan, before the new plan becomes effective?
3) Or, third option, do we wait for the new plan to go into effect because it seems to be a better option?
4) Where do I find details on the new plan?

Husband is a clinical psychologist, and has a colleague in UK who is sponsoring him to the British Psychological Society for Chartering. Our thought is that by becoming a chartered member, one goes a long way to providing provenance for his credentials!

I am neither highly skilled nor in a shortage occupation, but have received an employment offer at a university, subject to final approval by council. ("Piggy-backing" on a colleague's recruitment package.)

Any and all advice you can offer is gratefully accepted! Thanks.