is there an alternative to a lien in Kentucky to protect a GC for payment?

There are a number of alternate/additional steps you can take, including having the owner sign a Note and Mortgage (a type of "lien") and/or or a contract that provides for interest and attorney fees, and costs in the event of lawsuit or arbitration for payment. If you are trying to avoid the paperwork of a lien, these would also require a fair amount of it.

The best advice is to choose your customers carefully. Unfortunately, nothing can protect you if you are dealing with a scoundrel.