Just a quick note:
Try counting the stall along with a clicking metronome. When you say the “T” of “Ten,” it will naturally line up exactly with the click. But when you say “Seven,” the “S” will naturally start gradually and before the click, with the “E” coming on the click instead.
That means that if the max number is 7 rather than 10, the “S” of “Seven” will be too early and it’ll be hard to tell exactly when it happened relative to the disc being released.
If WFDF goes this route, it might be better to start at 4 and count to 10, instead of starting at 1 and counting to 7. Or it might be better to replace 7 with a different word starting with a plosive consonant (“time?”)