You will get to keep your low mortgage interest rate on your current property, and will still be able to use the benefits of a primary residence (lower down payment, lower mortgage interest rate) on your next purchase, as long as you have stayed in your current home for 1 year or longer (and there some exceptions to this as well). 

Make sure to present detailed and transparent deals, emphasizing the benefits and exit strategies.

Not only will you save money, but you’ll also gain valuable knowledge and connections that can benefit you in future projects.

You benefit by having what I call “instant refinancing” by having access to essentially as much equity as you could ever have without selling.  

There are many benefits to carrying a mortgage.

Since it's your first investment property, it can be a double edged sword since yes a PM can help you and be an expert voice but but if you don't know what you need or your management style yet, it might also not benefit you.Honestly, I'd try managing on your own for a while, and look up property managers in the area while you're at it.

Many do get a better idea of the benefits but also the challenges of self-managing by diving in.

Yes, management is more intensive, and 50 units is nearing the size of facility that having a small on-site manager could be a benefit for oversight, management and leasing.

I really hope they figure out a way to extend this in the future because it’s a huge benefit for real estate investors like us.

Equally important are looking in areas where the municipalities have ALREADY approved of them and provide benefits to the continued development of them.