I found the perfect solution for my needs. Before buying anything else, I experimented with what I had on hand and that included some really old Audioquest squishy footers, the kind you can literally ball up in your hand using a tight grip. You know, the ones that leave that messy residue wherever they're placed.
It wasn't half as bad as the Herbie's extra firm squares but still it fogged the highs and surrounding air. Next up were some Les Davis constricted layer damping pads, which are about as thin as two sheets of paper. Using three at each end of the Niagara 1200 (the pads are wide enough to support the width of the 1200) brought about a wonderful increase of body in everything, especial the bass. Not a hint of texture or detail was lost at the expense of some really thickened bass which was very tactile in feel.
Vocals took on a level of realism making it all the more corporal. Think mouth, throat and chest. Highs were more fleshed out as well but I thought it could use a bit more air and lightness. Taking one pad out on each end was the ticket. No loss of body with an increase in air, decay and extension.
It seems the light weight of the 1200 (just over 15 lbs) didn't take to the type of footer that a much heavier item would need. I had a similar experience with my OPPO 103 when I tried the Isoacoustic Oreas as footers: it just killed the highs and bloated the mids and bass. Going with the Les Davis pads under the footers solved that as well, and the OPPO only weighs about 11lbs., so there's something relatable here.
All the best,
Nonoise