Hi.
I've stumbled across a few situations where I had to do several dicerolls in order to succed.
Example: Squishing Edowin's tadpole and (iirc) the Nettie situation.
This is less than ideal design. If something should be hard to achieve then up the target difficulty. Don't make us roll twice.
Noone is is saying "Ah, but did you really hit" and make you roll again when you hit a goblin the first time.
I have thought about this problem quite a bit. What I think they should do for these scenarios, is require "different" dice rolls. Have the NPC try different tactics against the player, not just force a repeat of the last BS ability check. Maybe start involving Nature/Arcana/History as well as other stat rolls.
The Nettie situation has you just trying to persuade her a bunch of times if I remember, which has you rerolling the same check. Nettie already wants to kill you, maybe she asks you a question that requires a medicine check to maintain the persuasion like "I want to believe you but can you convince me {that you just havent noticed the symptoms}{that the transformation wont take place} at which point the player can explain the "Day 1, Day2, process of ceremorphisis that Gale explained earlier" as a medicne check resonse rather than another generic Cha check. Conceptually this is her trying to resolve your presuasive argument.. rather than require more persuading, she evaluates the one roll you did with further information. (Oh yea, some medicine words ought to show her I know what Im talking about... ah maybe if I toss some Aracana jargon she will believe I can keep it under wraps and wont transform) OR she wants to know that you know enough about your condition that you would at least kill yourself before changing, like "Do you know when the right moment to do it would be? (Medicine check) if you wait too long then you will transform and you wont be able to end it"
I remember the Necromancy book being equally annoying... I didnt even save scum it, I just let it go after it failed the second roll that was exactly the same skill check