im a bit like mh on this
sometimes an engine pops out with features i had as an idea and wanted to test and if i found it satisfactory i shared the code so anyone who might find it usefull could have a go at it
examples like early md3 support for quake alltho the base work was done by the guy behind the Qure engine i refined it enough to call it my own work in the end "newer got multimodels working tho hehe"
as for doing my own port from botton up i would if i actually had the
required code knowledge but i dont, i learned what little i can reading tutorials asking questions on qsg and a few times teaming up to squash a bug.
actually pretty funny when i first showed up on the qsg boards way way back it wasnt with the intent of learning how to code but because i needed help setting up a quake server

the guys back then kinda shuffled me in to experimenting with stuff i didnt have the wildest idea about and after some trial error i got things working and the intterrest came shortly after
