If you want an even cleaner boost you could try an MPF102 or J113 that I sell as a replacement. (I think I sent you some) as it will yield less distortion at maximum bias than a 2N5457 only if that is a thing you are wanting to try of course. It will require an approximate 2k4 resistor to Drain modification. This would then be a more accurate version of a Stage 3 Boost that I came up with about 10 years ago. That circuit was based on a Fetzer Valve a few years prior to me releasing the Stage 3 but at that time they were only showing the use of a J201 or 2N5457 which both yield a good but more colorful boost. I also noticed not long after the Stage 3 had become popular they added an MPF102 version with its different Bias value to their page which is fair. While I would say neither idea is completely original in the grand scheme all three versions offer a noticeable difference in distortion and tone.
I personally prefer less distortion as I do a lot of stacking as you may have guessed (as well as play fairly loud) so for me at least it would be a thing to try. Thus the Stage 3 (when using the J113) with its characteristic clean boost especially in the Bass and Top End became my perfect add-on gain stage or buffer.
You could also test this idea by simply placing a Stage 3 Boost (separate pedal) in series after a Sunn-T by turning it off and on to see what you think. I stack a Stage 3 with many of my circuits with excellent results.
Here is a good episode of That Pedal Show where they talk about stacking and do some great comparisons.
As they like to point out there are no real right or wrongs, just preferences.