there is a market crash coming2021, Construction will tank! 

Rates are going to stay low for a long, long time because there's no real ability to raise them without tanking the economy.

It will be a great investment in learning.We only do Self Storage, thus the following are worthless to us. 

Not an enviable position, by and large :) Move to passive investing in apartments and industrial and self-storage and data centers as soon as practically possible.

Putting in sweat equity to BRRRR a SFH into a MFH with limited cash is what I've done, so makes logical sense to rinse and repeat, but what's changed is my financial position and it's a whole different RE landscape, so hopefully others can relate that there may be alternative RE options that make more sense based on one's situation and the market (eg. syndication, partnerships, self storage, or just waiting, etc). 

If so what are some target Delta's in different asset classes such as Multi-Family, Self Storage, Mobile home (I have heard a target Delta of 3 is desired in Mobile home class). 

They are around a 1000 square feet max.The minute interest rates rise, and that's inevitable, it's likely the market will tank.

The only catch was that it was still on a septic tank despite the availability of city sewer.

I go to places like Construction Junction and Habitat for Humanity Restore to buy vintage glass light covers and doors (I much prefer a vintage wooden door over a cheap hollow modern door - and the modern junk is more expensive - I can usually get a used wooden interior door for $10-$20 bucks each and it looks great after it's painted).I also buy used storage cabinet/counter combos and put them in my smaller multi-family properties because those typically lack enough cabinet and counter space. 

I built my hot tub from a feed trough, some iron pipe and a water holding tank from an RV.