I strongly recommend ‘Consular processing’ to avoid status issues.
H1B change of status issues with h4 EAD
If you opt for H1B change of status, the change can happen anytime as USCIS can approve H1B anytime without any prior notification.
Once the change of status happens, your wife is on H1B and not H4.
She can only work using the H1B at that time and then only with the H1B sponsor employer.
This causes issues if she is currently working using H4 EAD as you are no longer on H4 status.
You have to immediately stop working for the H4 EAD employer if its different than the one who filed H1B.
H1B consular processing
With H1B consular processing, you control the date as the status won’t change from H4 to H1B on the H1B approval. You will need to go outside USA, get H1B visa stamp and then re-enter using H1B visa to get on to H1B status.