Current company layoffs - should i join on H1B Transfer receipt?

Due to covid situation my current company has laid off most of the employees and I am also impacted due to the same. My Spouse is on H1.
My Current H1 with the current company is valid till next year.
I am trying to figure out the options I have.
If i get a job during the 60 day grace period, is it better to join on the receipt notice or wait for the approval and then join.
The reason I am asking is
If i join on the receipt noctice and H1 transfer has issue, will i be able to change my status to H4 ?

Please read the options in case of H1B layoff here.

Thanks for the prompt response.
To add little bit more details.
We were furloughed from April end and the furlough was till end on July 12th
Last week of June we got a message saying we are laid off.
We got regular pay check of for april, 0$ may. And for June we got the final settlement.
Please let us know what is the best option I have now. Do i change to H4 or do i have grace period of 60 days for finding a new employer.

I suggest to talk to an attorney for your situation.

Thanks @Anil.Gupta for the response