It would be important to focus heavily on buying the right deals, as this strategy involves substantial leverage. 

As for snow removal and mowing, our transition months where the grass is dormant, and we aren't getting any snow is fairly substantial (spring and fall).

On the other hand, apartment syndication offers substantial economies of scale, which seems to be a common transition for many real estate investors, as I’ve heard on numerous podcasts.I would love to hear your thoughts on which route you think I should pursue and why.

I won't tell you what to do but I will say that with real estate, headaches and substantial problems like the plumbing problem you mentioned come along from time to time.

We had to give up substantial equity, just for this signature on the debt. 

The three in personal name have increased substantially in equity, I was going to tap the equity and reappraise etc looking at 4-500k of additional equity, these currently have separate notes in the 1st position of 3.35 30yr fixed.

While I have gained substantial knowledge from books and podcasts, I am now seeking a mentor in the area to guide us through this journey.

do you have substantial savings? 

However, this isn't to scare you away, because I was house hacking my expenses dropped substantially and I was able to pay that 20k back pretty quickly.

The interest paid on a HELOC may be deductible if you used the funds to "buy, build, or substantially improve" the first home.