I think the Skinny Peacock does it for me. Exactly what my hunch is. I think the designer used some dedicated thinking on how to address various aspects of 12 string guitar construction:
The 'inner bridge' is shaped for intonation only, with little or no string groove, the ideal configuration for any chordophonic instrument (eg: PRS wrap-around bridge).
The 'outer bridge' (rearmost) has the slots to ensure string spacing and negate the lateral string break-angle created by the tapering angle from the trapeze tailpiece.
Depending upon string guage, there exists upwards of 250lb of force, when a 12 string is tuned to standard pitch. That is a lot of tensile force and on a traditional 12 string, with pin anchors, that force is attempting to pull the bridge plate up and forwards. This is the main reason why acoustic 12 strings are prone to 'bellying', where the soundboard is warped upwards, throwing-out string action and thus intonation.
[note: all traditional acoustics are 'flat-tops', there should be no arching visible on an acoustic guitar].
One way of alleviating that tendency, is to equip the instrument with a rear-block mounted trapeze string anchor/tailpiece, thus transferring that tensile force to the rear block, this in effect has the opposite reaction, as the string tension has a tendency to push down on the bridge/plate/soundboard thus increasing resonnance and negating any tendency for sounboard bellying. The second bridge therefore would also assist in that endeavour.
The warping/bellying of acoustics is something I have considerable experience with, as I live in an aluminium box in Cornwall UK, where it is very damp, most of the time. As a result, all my large steel-strung acoustics are showing signs of bellying, especially my 12 string. On my Yamaha Jumbo(6), I'm experimenting with a cantilever system, that counteracts the tension, by use of a fixture on the inside of the bridgeplate, transferring that tensile force via a rigging screw (bottle-screw tensioner) affixed to the forward neck block. This idea was inspired by the JLD 'Bridge Doctor' although my design uses tension instead of compression to solve the problem.
The 12 string is being fitted with a trapeze tailpiece, as seen in this Harmony, so I might as well adopt the same two-bridge configuration too.
The roundback acoustic, being mostly plastic, is not bellying so much, but it's not flat either... I'm toying with using a form of string-thru to the rear, but on an acoustic with a plastic bowled body that poses another set of challenges.
Finally, I must say that Harmony guitars are well respected in the folk circles of Kernow and the UK. They have beautiful resonance and that 12 string of yours Topo is exquisite, you are a lucky person to own such a delightful instrument ;=)