Hmm... Let's skim though and take a look at what we know, try to get things clear.
We see in
this post that the fungi puff out spores at random, whether you are there or not. That was our introduction to them.
That post also adds that these puff 'explode when exposed to fire'. So, answering
sunnyVoid's question, the presence of open flame results in explosions.
If you don't bring the torches near them when they are puffing they should not explode.
Roald's 6- on
investigating (even with Decipher) means you
learned that you
can not predict the puffs, nor do you know how to set them off... or avoid setting them off.
You also
learned that the explosion is quite large.
Roald had walked all the way back to the distant group before the explosion happened and
wood-shrapnel still almost hit you guys. Even a 10' pole and armour (or even a
wall) leaves some risk. If the players choose to take that risk we will ask the dice how it turns out, so it has the potential to work (I don't like shutting down ideas).
Dirk suggested two strategies other than the forced detonation. All options can work, but you probably need to decide which to use.
I am not sure where the 6 second delay came from. It is explicitly not predictable and just
putting a torch near it does not immediately make it activate.
You are welcome
assume it is a set delay, but will soon learn otherwise (without much extra added risk).
Waiting for the process to start and then all running past --while it is happening-- makes no sense to me. That seems like the worst possible strategy, and the most likely to get everyone blown up.
If you want to go with that course of action, don't be surprised when you quickly learn the downsides. It is reasonable for the character to think it could work, and the dice may smile upon you, more experiences lead to more in character knowledge.
If you need more data, ask.