I'm not sure how to feel about the mechanic, but it would be the ONLY way to be faithful to the tabletop without a confirmation prompt at literally every action taken.
Sorry about missing your post on the issue, following mega-threads isn’t easy.
I can see an alternative to a time-based system for Cutting Words that doesn’t prompt incessantly. If the prompt appears only when the d6 matters, there would be far fewer (if any) unnecessary interruptions.
The pop-up would only appear if the enemy’s d20 roll plus modifiers beat the target by 5 or less. If the roll either failed or succeeded by 6 or more, subtracting a d6 wouldn’t matter so no pop-up would even appear.
Since this is a buff to Cutting Words, I recommend not telling players what the actual roll is at this stage, just that CW could work. (The game already reveals all ACs and DCs anyway, so showing the roll the way 5e does it would let players calculate exact odds, which 5e doesn’t allow without some work.)
This has the added bonus of not requiring a special UI for Cutting Word’s prompt, since the prompt’s very appearance on screen would be all the information a player needs as to the enemy’s roll: it’s within CW range.
I hope a similar system gets implemented for Bardic Inspiration, though it wouldn’t work for Portent. But if I understand mrfuji correctly, Portent isn’t in the player’s handbook, which neatly solves any technical issue by not being implemented in the first place.
