The TT Mayhem doesn't really need a drive-type booster to bolster its performance, I just did it to convince myself that some pedals are better left alone. What I hear from this line-up is an excess of bottom end even when my EQ for both pedals had the lower frequencies reduced.
However, I subsequently replaced the TK with a TS7 & it really made quite a difference in terms of definition; we now understand why the tubeless Tubescreamers are effective in this application.
Also, the TK's in-built noise reduction (that VOID control) unit is very effective to such an extent that my BOSS volume pedal was unnecessary in this set-up.