I don't even think that's the optimal way to maximize production, despite the amount of times it has been posted here. For one, it relies on one playing on Marathon speed, which one has to imagine a small fraction of the player-base regularly uses. Secondly, it is very difficult to pull off if you are not on a real-world map, as the civ 6 map generation doesn't tend to produce the concentrated about of forest required for this strategy. Thirdly, as the minimap shows it absolutely obliterates the AI's ability to function, and I imagine OP isn't as interested in a specific set of game settings that are not only taking advantage of an exploit (infinite fires aren't meant to be happening), but also completely removes the challenge...