2X Close CtoP and 1 App/App Date

Good morning/afternoon-
Would a guru be willing to point me to the area in TILA that discusses how a 2X Close Construction to Perm could/would/possibly should have 1 application/application date? I know the rule does not come right out and say it, but it's written in a way where the FI either has a take-out or commitment letter from another institution if doing the Construction Only, OR the FI assumes it will be responsible for the permanent financing as well, and creates the end loan, using the application date of the construction loan...
Can anyone help?
Thank you.

Thank you-

Official Interpretation

19(e)(1)(iii) Timing.

See Comment 5. It all depends on when you get the specific application for each phase. If you never get an application for the permanent loan, you have no responsibility to issue an LE on the permanent loan.