I don't know NY law, but in AZ, you may send two certified letters. 

Ask for their advice and maybe even something a little corny, like whether they’d be willing to write a letter of recommendation for your lender when the time comes.

Maybe a mix of both is the right answer for you.

I haven't hit it hard yet this year,  trying my hand at pre-foreclosures.I don't use a CRM, I'm hand writing letters and reaching out according to a criteria I dictated.  

Also in my experience it was a waste of time to send letters or any kind of marketing.

Some lenders may also want to see law and ordinance coverage in your insurance and perhaps a rebuild letter from the city stating that the property could be rebuilt as a residential 4plex if destroyed. 

They claim these are B markets and I saw someone in Reddit mention Lubbock Texas which has mixed neighborhood scores.

I would also have an attorney send a demand letter. 

An example of this would be mixing your personal money and LLC money in the same bank account.3.

The solar system adds no value to my property for rental purposes, and I may even be ripping up the roof & replacing it in the new year.Beyond sending a nasty letter through my attorney via certified mail, demanding the company come pick up their equipment, am I required to take any further action or fulfill any obligations regarding these contracts?