An adjustable string width roller bridge is certainly a nice idea, but probably not that Schaller. Or not without further hardware. The existing kit posts are 6mm diameter, not the 4mm required for the Schaller. And the insert threads are M8, not the M5 the Schaller posts use, so there's nothing to hold the bridge in the correct place (there'd be so much movement available that you wouldn't need to be able to move the saddle positions!)

Now you can get 8mm to 4mm post conversion inserts, so you have a threaded post sticking up like on a Gibson ABR-1 bridge and you'd need a roller thumbwheel. But the Schaller bridge isn't designed to work with that type of post and wheel arrangement, so you'd have to keep reducing the height of the 4mm threaded post for coarse height adjustment and have a very limited amount of thumbwheel travel for fine height adjustment. But that's far from ideal, and it's expensive.

Otherwise you use it and fill the old post holes and drill new ones for the narrower inserts. As long as the bridge is low down (and it should be because the neck angle is hardly generous on the kits), then the bridge should cover up the filled post area.

There is also the issue that the Schaller bridge has a 14" radius and the kit necks are 12". As they are rollers, you can't adjust the saddle notch height, so you are a bit stuck with a slight mismatch between relative string heights (unless you have a 2" high action). You could of course profile the frets for a 14" radius if you have a suitable radius block, but then you need a fret profiling file and the ability to dress and polish frets. Frankie can do it I'm sure, but the work (and cost) keeps piling up.

Allparts, in theory, do an offset 8mm to 4mm post adapter that's eccentric, so you can adjust the post distancing and position slightly. I've been looking at these for use myself with my very wonky GSM-1 bridge, but they are out of stock and they may not do them any more, despite still being listed. You'd need to use these with a bridge with 4mm post holes, and preferably a Nashville style bridge with the wider saddle travel, as the offset in post position will move the bridge forward or backwards slightly .

A couple of bits of 12mm dowel and an 11.5mm drill are certainly the cheapest option, but there's the re-finish around that area to consider.