> However, if I discover I need to look something up, a hard block on internet access would be a problem.

When I'm in "writing mode", I forbid myself from doing quick lookups, because I can almost never stick to the "quick" part of the process, and end up chasing rabbits. Instead, I just put something like (verify) or (research to confirm yay/nay) while writing, and move on to what I can do in the moment. Then much later do I go through with a "editor" mindset and address all those things in one go, rather than in the moment.

I guess kind of like picking work into a queue rather than doing it immediately, and leaving it hanging until I can work through the entire queue in one go.