Fencer: since I obviously misunderstood the implementation of the Fischer clock here, would it be possible to implement a setup modelled on the function of standard chess clock?

That is: have each player allocated a TOTAL time in days/hours.
Only one counter decrements at a time, the one for the player who has to move.
The clock for white starts at the creation of the game, or maybe not, the counters may start when white makes the first move.
Maybe also implement a Fischer increment for this model.