Thanks for measuring this so carefully - you were right on all three points. Fixed in the build that is up now:
- The fuel gauge and the "Fuel" number in the upgrade tree header now count real seconds (fuel / burn rate).
- "Burn x/s" is always shown, also after you own sconces.
- Upgrade cards that change the burn rate or the fuel now show what the next level does to the burn rate and to the torch time in real seconds.
- The page now says about 50 real seconds for a fully upgraded torch, not 90.
The balance itself is unchanged.