It sounds like you need a reliable and trustworthy partner to help you navigate this transition seamlessly while keeping your solo 401(k) on track.I’d highly BiggerPockets Partner for this, Equity Trust, a top-tier custodian in the industry.

Sounds fun. 

Also - it sounds as if there may be a deficiency here.

They don't care when you try to explain all the future projects, they actually hate hearing that since it sounds like a scam, when an investor says, "Give me a good price and I will have a lot of work for you" it sends chills up their spines. 

That said, if managing sounds overwhelming or you’re strapped for time, hiring a property manager from the start is a perfectly valid option.

Sounds good!  

It sounds like you stand to net (before taxes) about $4.3 million.

Sounds like it makes sense for you to partner, I would suggest: spell out responsibilities very clearly, how you make decisions and most importantly: have a very clearly spelled out exit. 

I don't like AI descriptions (sorry @Andrew Steffens).They look and sound completely like it was written by a bot, which it was.I like to write my own copy for listings and I respond directly to all guests, inquiries and issues.

Doesn't sound like any of this has been provided.