Simultaneous H1B and H4 visa, can I re-enter on either?

Does anyone have more than one valid visa stamp (H1B, H4) and been through the experience of intentionally reentering on a visa of their choice? Please let me know.

My wife has a valid H4 visa stamp and EAD based on my H1B petition. She recently entered in the country on H4 visa. Since then her H1B extension application also got approved, as it was filed with COS, her current status is now back to H1B.

She is considering to switch employers and in order to do it quickly instead of waiting for H1B transfer, we are considering for her to re-enter country again on H4 visa.

I am wondering what would that look like at the immigration counter at the border and if there are any risks associated with it?

Usually, most of the times, the Visa officer cancels on the visas, if they give a visa, unless it is B1/B2. They put in a stamp calledCancelled without Prejudice.
Discuss with your attorney on this and plan to do re-entry…if her H4 is valid, she should be fine, in general, to exit and re-enter using H4 and showing your H1B approval documents.