Tattooed - try moving the Herbies lower on the glass of the tube. They do really work well and wick away the heat. If you put them lower, some of the bloom returns and the treble is more in line with the rest of the audio spectrum
Tuning your tubes
Two tuning tips for tubes:
1. Treat the bases, not the glass with SteinMusic Maestro
2. Use a 1/2 inch ball of BluTack on top of the tubes
In my experience tube rings like Duende Creatura or Herbie‘s kill dynamics and produce unnatural treble. The above two ways are better ways to control vibrations and ringing. For small signal tubes without a base I have found EAT dampers and Mad Scientist Tube Toppers to work best.