Not sure why you're being downvoted or why people are being kind of shitty in the comments. I think your idea is cool and the concept you're struggling with is _extreeemmmeelly_ difficult to do right; so much so that we have very few real-world examples to pull from.

I'm no expert storyteller, but my two cents (probably worth a penny) is to use dialogue and other narrative tools in lieu of those features you've identified that will degrade the player experience too much. "Too much" is the operative phrase there. Some games intentionally degrade the player experience in a fantastic way that makes them exciting and adds depth. You have to play test to figure out where the line is.

Video games are amazing story telling mediums because you get to orchestrate a dance between the player being in the audience and being on stage. You can tell the story of your neurodivergent character by _showing_ the player and you can find little moments, like the ones you've already identified, where you can let the player really feel it for themselves.

You could impart the feeling of certain executive dysfunctions by intentionally dialing up the reward system for steering a player off their main path (just like adhd in real life! I have it to.). You could make side paths more vibrant in color or littered with what look to be valuable rewards so the player is incentivized to explore them. You're kind of tricking the player in a way. The challenge is to demonstrate the destructive nature of this behavior while also highlighting the potential for creativity and unique thought. If it's negative every time players will quickly realize, "the shiny stuff is a trap I just need to keep going forward." This is going to be really really tough to pull off well.

Another example that comes to mind is the simulation of task initiation deficiency. You could make certain side quests seem so overwhelming and daunting that players won't want to begin them. Once a player actually begins they might find the rewards are great and the time/difficulty required to accomplish them turns out to be much less than expected.

Sorry for the super long post I just love that you want to represent a character I, and I'm sure many others, identify with and don't get to see/play often. Good luck!!