Granted devaluation is a mess, but this situation does not require a rules change. If the whole start zone has no lift, if many pilots cannot stay up, then the task should not be opened. If the task is opened anyway, the CD should cancel the task when it becomes clear that an unfair situation developed. If the CD does not cancel the task, pilots may protest. There is precedent from Parowan, when pilots at the end of the grid had no chance to start, and the protest was upheld.

11.1.3 A valid competition day is a day on which every regular entrant is given a fair opportunity to compete,...

10.8.1.2 After the announcement of task opening time, the CD should consult with the task advisors as to whether the selected task is fair and safe.

3.1.3.1 ... The CD ...is responsible to the SSA for insuring compliance with these rules and fair competition.

(also search about 5 other instances of "fair" in the rules)

You know the process, put in a protest ASAP.

John Cochrane