A mustsee when doing TF autographs! Testflight signed source quote list.

Apps downloaded through TF signature can be used for up to 90 days. The 90 days here means that after the product is released, Apple will provide 90 days of testing time. Apps that have been downloaded after 90 days will also be prompted to expire and crash after clicking. The download address will also be invalid. If the product is re-released and updated midway, the download address will have a 90-day validity period again, and users who have already downloaded it will also have a 90-day extension if they download again. So in theory, if you continuously release new versions of iostestflight signatures, and customers download the updates again within 90 days, they can continue to use them.
Welcome to inquire via telegram, thank you.
@mrpankou