Investment Info:Single-family residence fix & flip investment.

One thing that we were not prepared for was the new lender required that our tenants have a signed lease agreement before we could move forward with the new house.

There is nothing in the original post that stated the resident's situation was anything like yours.  

This is when you buy a primary residence (1 to 4 units, the more the better) which you can usually get for a very low down payment and get the best interest rates on and then rent out other units and/or bedrooms within your unit to pay for the mortgage and other expenses.

Also should I send him a notice at one of his old residences ?

Time is critical, especially in competitive markets.Clear Offer Terms - Present a firm offer with terms that make the seller feel confident that you can close fast, with minimal contingencies or proof of funds.Due Diligence Preparation - Have your financing lined up and know your repair/rehab costs in advance so you can move quickly without second-guessing.

Put the profit towards a new Primary residence and ~$50k towards a rental property.2) Rent it out and eat the cash flow loss, hoping rents increase.

I am new to real estate investment and planning to start ramping up long term rental properties in 2025, however my first two primary residences were both converted into MIL's and rented within months after closing which effectively followed the House-Hack tactic (we currently rent our furnished basement to primarily traveling nurses for 3-6 months at a time which covers 70% of our mortgage).

.: There are companies that provide this and I even believe some do a revenue share with apartments.We had looked into this a while back for some of our properties.Not a bad revenue stream and a nice little perk to have new EVs charging near the clubhouse/office where new prospective residents can also see them. 

I'd want to know more information to make a good recommendation, but it sounds like you would have a strong argument if everything else is the same except for location.MP tasksTenant Management:Showing properties, screening applicants, and preparing leasesWelcoming tenants and addressing inquiriesCollecting rent and managing evictionsProperty Maintenance:Cleaning, repairs, and inspectionsAdministrative & Marketing:Supervising staff, purchasing supplies, and promoting rentals (ads and website)