I had H1-B and I-140 approved. I was working more than 10 years in the USA but lost my job due to current situation. As it was close to grace period, I’ve applied for COS on my husband’s H1 – and he also has I-140 approved long time back.
Yes, you can apply for H4 EAD with the receipt.
In fact, you could have applied for both at the same time. Just attach the receipt notice of COS and submit form. You may read below