Van safety is cool yo!
I recommend having a gas leak detector, a carbon monoxide detector and a fire extinguisher at minimum.
I put my Carbon Monoxide detector under the chair.
My fire extinguisher has it’s own little alcove – it feels out the way (but easily in reach) and does not affect the over all look of the van very much.
Fire extinguisher alcove
Again, get your systems checked by people who know what they are doing. Your life is worth it.