Do I lien the full amount or just work completed as of right now that is owed? Still actively wokring on the job.

I am a GC building a house for a homeowner in Tennessee. The homeowner is dealing with theirconstruction lender directly, meaning I am not paid by the bank but by the homeowners and I have a cost plus contract with the homeowner. We are still on the job but the owners currently have an outstanding balance of $74,808.07 with us. The invoices are from February and March. The work to be completed within the next two weeks will be an additional $44,591.36. The homewoner says we are paid to date per their bank inspection percentage which is not true, and when we signed I was not informed of the banks payment process nor "percentages" since we are not billing the bank. The homewoners have added over $30k in change orders and in material cost increases which they have not informed their bank of. Alos, when they received the "notice to owner prior to commencing work" the owners owed us money (this is common with them), they immediately said "so since you're not finishing the job can we get someone to finish it." Keep in mind, we have never stopped working on their house even with them owing us massive amounts. I know when the owners receive the "Notice Of Intent" they will say the same thing. My question is, do I only file a lien for work completed which is the $74,808.07 or do I need to lien the full amount that will be completed within the next two weeks (electrical trim out, plumbing, cabinets and countertops)? I am worried the owners will try to close on their construction loan and my company will be stuck holding the bag for their house....