Do they deal in simultaneous/double closings?

While the purchase of multifamilies (& multiple, simultaneous VA loans) is allowed, it's to help military families get into a home, not acquire investment properties.  

The big complication is I have another flip project happening simultaneously with holding costs of ~$3400/mo.

A real project manager would be able to oversee multiple rehabs simultaneously and do what many GCs can't and might be a good 'next step' to start considering if multiple rehabs is your goal (and which seems to be the growth you're headed for whether they're for flip or hold).My real answer right now though would be to look at investing in a good property manager so you can focus on being your own project manager.

Simple, sell to him, then buy.....or sell and buy simultaneous, with your purchase agreement contingent upon his purchase.

Then simultaneously we get our buyers connected with a credit enhancement company.  

You should have joined all 3 simultaneously when you went to the local board in person.Membership should be immediate after you pay all the yearly dues and fees and you will start receiving materials from the National and State boards in the next few days and weeks.

I was in the process of making two simultaneous but separate 1031 exchanges from two SFRs to two MFs.

I'm *considering* targeting 2 different cities at once, given that I think I have enough time and hustle to work on building 2 teams simultaneously.

They all capture your contact information and sell it at exorbitant prices to several agents simultaneously, which is why you're getting so many calls.This is the business model of the 2000s.