Voda La Void
Yeah, the flavor of that chord completely changes when I flat the 5th on the Bmin, and I do like the sound of that. But I also like the sound of the perfect 5th on it, even though it's clashy. Isn't that weird? I strum the F on the low E, the B on the A string, and the F# on the D string, and just strum that to hear the essentials of that combination, the clash. I try this in several places on the neck, up high, so I can get a good feel for it, and while I hear clashing, I still like it. I almost view it as an effect, rather than musical.
And that makes me question my musical sensibilities a bit. Seriously, if that clashing can sound ok to me, then what is ever going to sound wrong? I'm doomed. Ha ha.
I just picked up my guit to check on that chord (SONAR is ticking me off at the moment with some rando bug). Looks like that specific chord appears in F Locrian (and perhaps one of the Harmonic and/or Melodic minor modes which I did not check). So view it through the F Locrian lens when you hit that chord. The F actually (when viewed this way) can be considered the root, the B the diminished 5th of the Locrian mode and the F# is actually a minor 2nd (or in chord terms a minor 9th which is the same thing as a "2nd").
I'd consider that 2nd/9th a "suspension" that resolves to Root/Octave (F). When playing that chord alternate between that F# and F and you will likely hear the "tension and resolve" created by the suspension.
You are breaking the key for that chord though which is totally fine and I'm sure there is a specific cadence name for that movement.
F Locrian's relative Major is F# (or Gb because IIRC it is one of the keys that can be defined as either sharp or flat within the Circle of Fifths... I'd have to double check cuz it's been a while).
Anyway, don't worry. Your musical sensibilities are totally fine and I've used similar rule breaks to create dark tension for all sorts of material. It's obviously more of a metal/moody experimental jazz type sound but perfectly cromulent. :-)
Thing is it's IMPOSSIBLE to actually break the rules because the rules just readjust themselves to explain even the most (seemingly) nonsensical stuff.
Really modal/interval/chord theory as I've described it here is intended more as a tonal "yardstick" (I keep using that term but it really is a great way to look at it). You can remain within a key whilst not breaking any natural modal "rules" at all and write some great stuff.
However if you want to get freaky deaky you may always do so with abandon and not worry about the "rules" because no matter WHAT you do the math can "solve" it.
Look at a Slayer tune. Chromatic and skanked right the hell out intentionally BUT if one were so inclined they could take that atonal mess and solve it all... likely exposing moment by moment changes not just to the overall progression but within riffs.
I'm pretty good at solving this type of stuff in my mind but since I was constantly applying what I was learning to my instrument (guitar) I can solve keys/modes/chords far easier with my hands and ears. I find my root (or suspected root) and go through my options based on the notes already provided and extrapolate from there. I know the physical patterns so well and from all the scale practice by ear that it's easier for me to actually PLAY a part and solve it than on paper.
I think that is super important and kind of the point (if you are musician and not just a pure composer or theorist/teacher.. that's when you really need to have this stuff locked down).
Check out the chord progression in Jimi Hendrix' (and SRV's cover of) Little Wing. For the most part that progression sticks to E nat minor (relative Major G) but it breaks out if it at multiple points as the progression builds up culminating into those ultra skanky and atonal slidy chords that round out the progression.
That is similar to what is happening in your progression so I recommend goofing around with that tune to see what it shakes loose.
Cheers.