I think i know why you get the runaway from tinctures. They contain KI, try adding some peroxide to KI...it foams and decomposes quickly... I use I2. Solid elemental iodine, there is not even slight heating of the reaction mixture when adding the peroxide. Also you could heat to dissolve the Hydroquinone but it is not needed as it dissolves as the mix heats on it's own. I've done it where i dissolve it first, it makes no difference.

In fact I have first hand encountered the run away (mass foaming, boiling etc) when trying to use KI, and it happened with tinctures too. Yeah, the tinctures from a store, not povidone iodine. I am almost completely sure that is why it is getting out of control.

Terror I don't know what you are trying to get at...I've had success many ,many times..it is how i make my BQ, and it is a key reagent for me. So your guarantee is void! It has already worked using a few types of H2O2 (27.5%, 30% and 35%). Try it before making such positive statements!

To everybody here who may doubt me, just try the method I posted doing it how i said. It will work, you cannot substitute a tincture or KI in this case. I don't post misinformation, my only goal here is to make things more accessible or easier for people and give helpful information.
And terror, you use magnetic stirring with what I said, the reaction flask should be closed with a cold condenser. The heat is on low and it is removed before the mixture begins to heat on it's own. You could use a heat gun yes, a hot water bath would be too hard as you have to switch baths quickly. You won't be able to do it fast enough probably.

Hi Pryamid, I reduce the KI to elemental I2 through h2o2 and hcl so am fairly confident it is good quality. Basically what I was getting at was that my reagents were poor quality, hence the failed reaction. I don't think it would have worked for anyone..

Shake: I don't have any data for you unfortunately.