what should i use h1 or ead after 485 pending less 180days layof

PJ, Xiaobaitu, other experts:

Got offers after my 485 pending less 180 days layoff. I-140 was approved and will not be withrawn by ex-company. But, my 485 is still pending less 180days by now. H1b was terminated in the middle of last Dec. and was noticed by ex-company to USCIS in the end of last month.

What time is best for me to start to work in order to make my485 safe?
Should I wait 180days? In this case, should I use H1B transfer or EAD? Can I use EAD first, then apply H1b transfer later oo even apply for a new H1B?

Thank you very much