I didn't understand why you randomly brought VAR into a thread from a level 7 referee asking about dissent.
In the context of the opening post and following discussion it was confusing.
Dissent tolerance can often be mistaken as a reason for simply not dealing with dissent. That's the best advice I can give you. If you have got a player constantly questioning decisions, ask him to stop, tell him to stop, publicly warn him and then when he does it again caution/sin bin.
Even better when you have standout behaviour you can deal with.
@wazztie16 gives a great example, slamming the ball down although I'd argue this falls into the obvious category and can be dealt with with no management.
Action is much easier to deal with than words as often action is seen by everyone, sometimes only you and the player know what was said and that's harder to sell from an optics point of view. Words of disagreement are manageable using the Stepped approach, big clear actions (slamming the ball, excessive waving of the arms in dissent, booting the ball away to show dissent) are easy sell to move straight to caution/sinbin depending on where you are and your level