I'm concerned how fire placing feels like a legalized consensus cheat to me, and how i feel it is too easy to control fire to your benefit. So i'd like to propose the following to my group, but thought i could discuss it over here aswell to get even more input.

Houserule sketch:

1) When fire spreads, establish within your group a target space for spreading fire.
2) Roll 2 dice
3) Check conditions accordingly:

-If the dice show 2 elder sign symbols, spread fire in the opposite direction, if permissible. Else; in any other adjacent space not established prior to the roll.

-If the dice show 2 clue symbols, fire spreads to every space in the room of the established target.
-If the dice show anything less, go on an place it as established prior to the roll.

For reference, a MoM2 die has 3/8 chance of showing an elder sign, 2/8 of showing a clue, and 3/8 of showing a blank. I figured 2 dice with full pot checks yielded a more forgiving but still uncontrollable ratio than if simplifying it to just 1 die.

I hope this will help it become adequately risky to play with fire without bogging down the pace too much. Also it gives the pyromania insanity card a slight push. Any thoughts? Experiences on how you feel about fire placement?

14% odds of 2 elder signs, 6% odds of 2 clues - so it adds just a small chance of 'something different' but in a way that isn't too brutal. Not sure the entire room one is a good idea, with some room tiles that could end up being 3 spaces in a single spread, but with the odds so low, probably don't need to worry about it that much. I would say that need you are trying to address is more convenient direction, not spread rate. Rate messes with game balance, while placement generally shouldn't. In the admittedly few games I have played, fire really never felt like a threat. Mostly just a 'keep spreading it where it doesn't matter' kind of thing to manage when out. If it had a chance to somewhat randomly go in a way that wasn't good it probably would add more risk to it being on the board.

One thing you could try is use an arrow die. Warhammer has one. Then roll the die and follow the arrow

Thanks for your comments, i appreciate the input! I found cardinal direction/compass dice off ebay, they seem perfect for this kind of thing. I'll propose using them to my playgroup. Hopefully that will do, as it's as simple as it can get and doesn't add much weight to neither rules nor process.