Most of the trumpet players I play with usually play C trumpet in public, so I used to write only C trumpet parts. But there was some push back when I first started publishing, and many requests for B flat parts. Because everything I published back then was copied by hand, this was a real pain in the ass.
It occurred to me that pretty much every trumpet player on the face of the planet has a B flat trumpet. In my experience, many pros even warm up on their B flat before switching to C for the day because it feels like 'home.' So I went back to writing B flat trumpet parts with the thinking that most trumpet players that owned a C and preferred to play everything on their C were pretty good at reading B flat parts anyway.
I used to believe there was a discernible difference between a B flat and a C, but that was the hubris of youth - it is mostly attributable to the player. There's probably a trumpet player or two reading this that can tell the difference. It's splitting hairs though. There may also be some logic to trumpets and trombones lining up in the overtone series, but it's great players playing with a resonant sound that make music sing and ring - and well voiced chords.
Having been a Finale power user since 1990 (remember 3.5" floppy discs and thick-as-a-phone-book user manuals and reference guides?), I now have very little excuse to not publish parts in B flat and C except that it chews up a couple of minutes for every part to realign dynamics and hairpins. So I've slowing been creating alternate parts (there seems to be demand). I'm now even considering making all of my 11 piece charts available with e flat alto horn parts and treble clef euphonium to make them more accessible to the brass band guys.
Long story short - you can drive yourself nuts with all of this.
Write for the trumpet that you would like to hear (within reason), make alternate parts if you are inclined, and let the trumpet players sort the rest out. They will anyway.