Even if they would know, they wouldn't do it.
The aim of teams in the Warez Scene is to release things first (because the first to release something wins, get credits/new axx and so can leech stuffs from the others teams), so yeah, the less time it take to encode, the best is it for them.
Though they could afford good computers and do a fine encode at the same speed
And as it's some rips things and mostly not fansub, they are lazy and so, yeah, use automatic things to encode (it's not the same as someone who would do a fansub and so, knowing the time he spent to do it, want to try to get the best video quality he can).
Because, in this case, if people really want the original quality, the DVD is available as it's a rip.