I would follow up with him to confirm if he is still interested in submitting an application and advise him his wife will need to fill one out as well.

Can’t find any independent confirmation.

The plans are owned by the designer and his/her client.  

Does anyone have experience in raw land development or have recommendations on architecture designers?

I also have relationships with several real estate agents to confirm.

I have hired leasing agents, lawn care, cleaning and web/graphics design.

Having the GC license, the real estate license, being able to do all the designs in-house, and being able to manage the project directly.

Once confirmed that it exists, this may be what the deal could look like:-You draft out a contract with an agreed upon sale price & terms.

We’re trying to design a fair compensation package that aligns his interests with ours and makes it sustainable for him in the long run to continue to manage a growing portfolio.Does anyone have any suggestions regarding the best way to design such a package?

Now.... if they are moving without letting their employer know, that's a whole other thing.Again, I'd check with a lawyer or CPA to confirm.