I understand a work permit will help get you back into Thailand.

 

Does this mean a return flight can be booked? What's the current process and is it likely to change anytime soon?

You would need to do as per the requirements, so book ASQ, apply for an entry certificate, PCR test not more than 72 hours before the flight and a fit to fly certificate, booking a return flight might not be wise, as there are some unknowns, such as time required to obtain the entry certificate etc.

Are you on an extension of stay based on work and do you have a re-entry permit?