starks, with all due respect it does seem like you have a fair...

starks, with all due respect it does seem like you have a fair bit of reading to catch up so as to properly understand the subject.

e.g. your statement:- "Like i said, name the institutions who are screening TB 100% with an Igra, rahter than using it as an adjunct to the Mantoux."

NY Dept of Health is just one of many which now uses QFT exclusively. Not a TST in sight.

also your statement:-
"If you simply need to determine TB exposure versus no exposure (the objective of most of the screening that takes place), why the need to switch?"

You missed out the word accurately as in "accurately determine"

good idea for you to read some of the independent cost and accuracy trials of QFT vs TST. Actual test cost is a very small part of overall cost analysis, overall the QFT is cheaper.
Plus of course there is the dangerous situation where the TST has been proven many times to provide unacceptable levels of false positive and false negative tests.

No wonder the TST is on its way out and QFT is taking over.