My instructor didn't make a big deal about not hitting the pedal C either... he said don't worry about it ad it will come around in time.
I don't know this for a fact ... just my take on pedals. If you practice playing lower than the F# then the F# becomes less drastic and not the end of the instruments range. Sort of the opposite of Adam Rapa's "today's squeek becomes tomorrows note"
I do agree some trumpets are easier to play the pedal C on then others. My Bach isn't and since it's my main ax ... it's the one that counts .. well to me it counts.
Someone has to know how to rip a pedal C on this site