i think if you only combusted in it a handful of times it might be ok, but after some time of combustion the taste might be more noticeable.
i have a Left Coast straight tube that i use for vaping and will rarely combust in it, only burned through it like 4 times i think. after each time i did a ISO + salt wash and couldn't tell a difference taste wise when running a vape through it. however, i could faintly smell a scent of lighter butane at the downstem where you put the bowl.
truthfully, i think it mainly depends on how sensitive your sense of smell and taste are. i'd say im normal-ish and not very sensitive so i can get away getting combusting in a glass piece from time to time and not taste it with vapor-bonging afterwards.
do you have more than one glass piece? i have two, the Left Coast straight tube and a 12 arm bubb. i don't ever plan on combusting through that cause its my main piece for water filtration and it's my baby
if you have more than one and its not your most prized piece then i say go for it.