The bridge string length adjusment is to allow for different tunings

For instance :Thin LIzzy tuned down all their strings by 1/2 step - their open string tunings were

E flat - B flat - G flat - D flat -A flat - E flat

This gave then a lower rockier sound and the lower string tension would make their ' string bending ' easier

Jimi Hendrix also used this tuning

In both cases the bridge Intonation would have been adjusted to suit

Otherwise the physics of the neck would be incorrect