Wasn't there another thread with this topic and a few more posts?
I'm in the same boat - I have like a year, if that, of streak lt 4s left (they wear out fast) and one pair of streak lt 1's (they will prob fall apart in a month when I start using them because they are so old even though unworn).
The mizuno wave cruise is like 18/14 stack/drop. Similar weight to streak lt.
Mizuno duel sonic 3 is 21/17 and 6.7 oz I think. It fits much looser than the streak lt though. You have to buy from japanese sellers on ebay.
Saucony sinister is 25/20 and has weird lacing, but they work ok for me. At least if I don't run in them every day. I hear they are discontinued, but a few retailers still have some sizes if you go through a few pages of search results.
Descente made some shoes with around 20 mm stack height.
Fila KR6 might work. You can buy them from a Brazillian seller in any size but US10.5 (my size of course).
Some people wear xc flats (spikeless xc racers) - but those are too minimal for me.
None of these are great solutions or long term solutions - though if duel sonic 3 works for you, that shoe is at least still being made.
Its super frustrating that no shoe is filling this gap in the western market, but there seem to be very few who are in the gap.
Maybe someone can chime in with more ideas? Any prototypes in the pipeline with a low stack and a tight fit?