They will allow if you offer her way way beyond what she can earn in one night with ST, or if its already 2am and she will leave at 6am or if you look like superstar.
Anyway alot of these SYT even if they agree to LT, most of the time maximum 2 shots so better discuss properly. For me, I never understood the concept of LT, I just want to fuck and then do my own thing, but of course up to individual