I found the marked turret fine when I had a T50, it is easy enough to mark your click down then dial.
The un marked can be used to just mark your yards on it saves reading a click chart just dial what the wheel says.
There are people using both methods successfully so which ever you feel more comfortable with.
35yrds is my preference but lots zero at 40 yrds as long as you range correctly doesn't make a lot of difference.
Steyr LG110 FT, Sightron SIIISS 10-50x60 LRIRMH