I see the bug you wrote up here:
After seeing what you wrote though, I'm assuming that getOutput() method was maybe changed in relation to the new "steam" changes maybe?
The function getOutput() might be referenced elsewhere, and then if steam output is disabled, it multiplies that number by 5 to obtain EU output. If steam output is enabled, that number is multiplied by some other value to obtain the correct amount of Steam output. That way getOutput() doesn't have to know anything about Steam or EU... the later functions that call it can make that determination. Previously I assume getOutput() always assumed it was sending the EU output value.
FYI here's the steam comment I was referring to, however I don't know if this was done pre or post steam turbine nerf in RailCraft:
Updated to 1.108.71, adding EXPERIMENTAL Railcraft steam outputting reactors. I also separated the energy part from the core reactor, so there MAY be bugs with the regular reactor.
To enable them, you gotta set enableSteamReactor to true in the config, then reactors will output steam, balanced vs. the turbine output.