Not sure what you mean by "TSA post". A-West is (most, or, all?) international arrivals at PHL, and (most) international departures at PHL.
If you're connecting from an international arrival to a domestic flight, you clear immigration, collect your bags, clear customs, re-check your bags, *then have to go through TSA security again on your way to your domestic connecting flight*.
With A-West TSA now closed, I don't recall whether this adds more walking from after-Customs-exit connecting-flight-bag-recheck, or whether that particular exit was already pretty close to A-East (or whether there was a separate access to a TSA checkpoint for international arriving domestic transfer passengers; I've never actually made that connection at PHL).

I find it interesting that AA/BA do not find a way to pay for a private security force to augment the TSA A-West checkpoint, being that TSA closing A-West is a significant inconvenience for AA/BA international passengers.

(I'm scheduled to arrive PHL in a few days, and depart again in early December; I hope this mess has been solved by then, but for the moment my idea is to arrive early, check the airport's website's security lines status webpage, and consider walking from A-West check-in over to the C pre-check-only checkpoint...)