I seem to remember Bendalloy's speed bubble affecting the speed of which Furnaces smelt items. It doesn't seem to be working anymore.

Is it also possible for Speed bubbles to effect the furnaces in the Mod Iron Furnaces?

Yeah the patch was only applied in 1.19. I imagine the same code would work in the earlier versions though

What version are you using? This was broken at one point but I believe I fixed it in 5385c56

Latest for 1.18.2 according to Curse Forge! Is it possible that you patched this for only 1.19.2?

Allomancy: Version 4.5.3 - Forge 40.2.0 - 1.18.2

If you aren't supporting 1.18.2 anymore, I might give coding a second shot and see if i can patch it myself, (with your permission of course)

4.5.4 has been released with this issue fixed

49513d0