And when did your building permit get approved?

The value of 3 acres zoned multifamily vs 3 acres that has full entitlements (meaning you just go to the city to pay permits and start building) is significant.  

In hindsight it would have been better to have a contractor working under a fixed price contract to complete the work by a certain date including inspections and permits etc...

You will not prevail in a California Court if your PM permits weeks to go by before inspecting.

January 2024, and still as of now they haven't start construction and supposedly because it's a new year, all approved permits have to reapplied since they never started construction. 

You can do a ‘cash out’ refinance on the rental home as a permanent fixed 20-25-30 year loan to pay off the Heloc on the primary and most likely the equity line on the primary permits a ‘re-draw’ to utilize again. 

However the lenders will want to see the permitting completed before they fund their loan.

I'm assuming the developer has already paid for all of the soft costs (architecture, permitting) before you, the investor comes along. 

Avoid paying large sums upfront.Online Payment: Use secure online payment systems to manage transactions and keep records.Permits: Ensure all necessary permits are obtained and required inspections are passed before proceeding with payments.

Ft)The first thing I look at before viewing a property is the permit history.