The property I am on with them has been neglected to the point I received a notice of default.

I would be surprised if there weren't notices given to both the defaulting End Buyer (You're in default, you must close by X date or we're forfeiting your deposit) as well as the escrow agent (Buyer defaulted, see contract Earnest Money paragraph regarding release) prior to that actually occurring.

I think its because there are a lot of people pushing seller financing right now and private lending because most cannot make the numbers work on a property - so the gurus need something to be able to sell so its this is the flavor of the month. 

Outside of raising money from others or seller financing, I am looking to see if there are private or other lending options that could cover 10-20% of a downpayment on these loans with a shorter loan term of say 5 years.

Do not think you can get a hotel room during Semana Santa (Easter Week) with no notice!  

You can log into their daily 5 hours of zoom calls to hear them answering a variety of questions as continual learning and ask private chat questions on your specific needs too. 

So property is private.

There is running private credit and running MF and then their is portfolio mgmt.

I have a potential private lender, but I need to determine if this is a viable investment opportunity and explore the best financing options 

Ensure your flip profits exceed the LOC costs, maintain a financial buffer, and compare it to private or hard money loans.