h1 to H4-Urgent help reqd

[h1toh4]

Hi,
I got a COS from H4 to H1
Now I am thinking to go back to H1.
I want to know if it is necessary to work and get payslips after applying for H4(before getting an approval)
I know the process of getting an H4 approval will take at least 2 or 3 months
Is it required to work after applying for cos from h1 to h4 and before getting approval. If yes, what happens if i get laid off with 1 or 2 weeks notice

Please advice

Thanks