Ways to reduce Vgs range of Logic Level MOSFET
Can the simple RC and MOSFET circuit be altered, so that the turn on
Point can be precisely defined? (+- 50ms)

Yes, but you will have to add a component that has more accurate threshold voltage. An op amp or comparator could be used with reference voltage set by a voltage divider, like this:-



simulate this circuit &ndash; Schematic created using CircuitLab