Or get a full time job to pursue my goals sooner?

The only thing I am cautioning you on is your desire to get in sooner than later.  

We (my brother & sister-in-law) currently purchased out first investment property last year, much sooner (early 2021) than we had expected.

I have a horse that I’m conditioning to compete in an 100 mile horseback race within a year or two(which also doubles as my gym/workout).

Sooner or later they will hit their breaking point and sell it.

It will need Cap-Ex sooner or later, so BRRRR would be the ideal approach here; I'm approved for a conventional loan, but could start applying in earnest for a bank loan, or possibly pursue an option I have to partner up to make a cash offer (this deal is right around that 100k mark where my lender would only reluctantly do such a small conventional loan...another reason BRRRR is appealing).

So far I'm finding 6 month seasoning periods, which I will work with if necessary, but I'm hoping for no seasoning period so I can refinance within 2-3 months in order to acquire properties sooner.

It seems you'll need to give the 60 days notice without it being month to month as you stated, but that she may be willing to sign it sooner than this. 

Though tenants are paying enough rent to cover mtg and interest, the sooner the mortgages are paid off, the sooner I'll have maximum FCF without a mortgage to worry about at retirement.

The earlier you start, the sooner you can build a successful business and career.