I think I have figured out how to make this work
When I set this filter to less than 25bb it includes some hands which are not only 25bb effective.
It has a bunch of hands with deeper stacks for some reason (idk why)
But when I set less than 25bb and more than 1bb (or 0.5bb) the output is correct it seems.
EffectiveStackSizeInBBs>0.5 and EffectiveStackSizeInBBs<=50
So I was able to filter for 1-25 or 1-50bb stacks etc.
Still when I filter for all spots with stacks more than 1bb (which should be ALL hands right?),
out of ~100k hands around 10k hands dissappear (meaning those hands were less than 1bb effective stacks, which makes no sense).
I won't bother with sending hands for now, thanks