My provisional strategy is to put a room in a property up for rent while also living in it as my primary residence for a year. 

Where are the well and septic located?

Have you thought about trading the fiveplex for a Class B duplex in a Class B neighborhood and move into one of the units and rent out the other??

I would think about other options.1) Extension with current lender.2) Sell/rent - depending on the condition ?

When searching for properties I’ve come across a lot that current rents are below market rent.

I can get up to 30k/ unit for a multi family home in renovations but must rent to low income for 10 years."

If he files a transfer deed to the Land Trust or if he "sells it" then property taxes increase, the change in hazard insurance becomes a tangle.I wouldn't give authority to a bank person to collect rents, file evictions, deal with repairs... there are set up costs and on-going management costs.

The most obvious is that you will be able to offset your mortgage with renting out a few rooms.

We originally rented out a single room in the home to house hack, but after a career change and a bug move we decided to turn the house into a single-family rental situation.

Are the other units rented long-term with leases in place?