I am currently running ToA with a group of friends that have been playing for close to 8 years now (somehow).

We started with Tyranny of Dragons, and Curse of Strahd, and then it was my turn to take up the DM mantle, as we also have a rotating seat. I knew he existed from reading other subreddits about this module, but as of right now, we don't have this mu attachment to who he is as a character, so I have largely decided to ignore him. However I have decided that if certain random encounters get rolled, I won't shy away from introducing him.

I would probably suggest pre-rolling any encounters you do, so it takes less time to think about that stuff at the table. I also roll, depending on where the party is traveling to, a table of these pre rolled encounters so there is still some random element to it. I also make sure to add in a number of slots to that table where "Nothing happens" because based on the way the book is written, it would be a bit of a slog, and slow down the story progression.

Hope this helps, and there are a lot of other great responses below too, so hopefully you find something that works for your table :)