jobo
Grandmaster
well they are pretty similar,, i dont think thats a back kick in either, i have done a little tkd, back in the day, but if one of our tkd exsperts contradicts me, okKarate terminology for what constitutes a back kick may not apply in the context of Taekwondo.
but thats not really the issue.
one, why is your side kick deficient,, such that a hybrid or at least badly excuted back kick is superior
and b, if the kick works for you, it doesnt matter what it is, unless somethibg else would be better