I Use 1k vr.
the spot on the VGA is 110ohm, if you solder 100ohm that will be around 55ohm and for me that would mean 1.6 - 1.7v is my guess.
so i use 1k vr and dial it to get 1.5v for ln2 (dengerous for pwm), but when i measure 1.5v on VGA the resistance is 85 ohm at the mod spot. so i dont know what 55ohm is going to do if you use a 100ohm vr