I wouldn't worry about it. You'll know pretty quickly if they've got a problem For me it was seeing a single abnormal dropping when I walked in the pen. Gathered a sample and took it to the vet to determine what was up, that's how the capillaria was found. I suppose if you are really concerned about it you could take a fecal sample to the vet before you worm. That way they could tell you if they see anything and if they do what it is so you'll know which wormer to use.
Even asking other poultry folks in your area might not work. I've asked others here but no one says they've had any issues. But my birds do get to go out and be chickens where these others are kept penned in doors.