The advantage of having a temperature-controlled forge is the control of oxygen. In a temp controlled forge you can wrap the blade with a steel foil and basically eliminate the O2 near the blade. I suppose that you could do this with no temperature control, but having visibility of the blade color is key without having some type of temperature readout on the blade.
Sounds like you could wrap the blade in the foil and include an unwrapped sample of the steel stock in the forge.
Use the scrap piece as a temperature gauge.
