This is not related to LT 4.0, it has always(?) been the case. The reason is that there’s no entry fsa.dict.speller.ignore-all-uppercase=false in en_US.info (source). As other people have wondered about the current behavior before, should we change it? The drawback is that less common acronyms like “PMN” or “OCA”, which are not in the dictionary, will be considered incorrect.
It would also increase the false positives for onomatopoeia.
EG:
His competitor had spun himself a score of 98, so Joseph spun the wheel as hard as he could.
##TRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRR-T-T-T-T-T-T-T-T-T-T-T-T-T-T-T-T-T-T-T-T-T-T-T-T-T-T-T-T-TICK-TICK-TICK-TICK-TICK-…##
‘Come on! give me a 100 or even just a 99!’ Joseph ‘asked’ from the wheel.
##… TICK… TICK… TICK… TIICK… TIIICK… TIIII-…##
'NO! Don’t rest on…!'
The game-host announced his score as “97… Sorry Joseph, but that puts you out of the game. Fred, care to join me for the final round?”
This was relative to tests. Even the best linguists and grammarians make general rules that have exceptions. One exception is a false positive.
What we can do is to reduce the bell curves overlap by improving rules, but there will always be false positives in every test (Languagetool rule). Specially, when we are dealing with especially designed examples, outside the purpose of any grammar checker, like:
it’s clear that you don’t know what false positive means.
a false positive is not an exception to a rule, it is a situation where something that is not a match is mislabeled as being a match. (a common cause of false positives is improper simplification of a rule, but your ‘definition’ switches cause and effect around)