So my Caravel makes excellent espresso, has adjustable, stable brew temperature thanks to a PID and even holds up fairly well on repeated shots. Now if I could just find a nice little steamer to sit next to it.
How about taking off the grouphead from a La Pavoni and bolting on a steel plate. Then leave the pitcher on the drip tray of the Pav and just use it as a steamer? Maybe with an upgraded heating element and a better steam wand?
A nice dual-boiler setup with small footprint, fast warm-up time, separate on-off switch, easy cleaning and great looks?

why kill the Pavoni by beheading? Just leave it intact sitting next to the Caravel, and then use it as you intended with the Caravel, and the option for the "2 Group (slightly different group configuration) double boiler".

I understand your sentiment, but I am merely looking for a dedicated steam only machine and as of now, the best option is something like the Bellman CXE-25:



But I hear it's really hard to make good microfoam with these.
A de-headed Pavoni will look a lot better and steam a lot better too!

There's so many discarded old Pavoni's out there with broken groupheads and all, but functioning heating element and steam wand.

This strikes me as one of those odd ideas where, sure, you could do it, but ... in a La Pavoni usually the heating element and/or steam wand or base goes before the group does. The La Pavoni will make a larger shot than the Caravel and one that's just as good, which will give you a nicer capp. If you find a Pavoni to behead, go for it. But in that case you're not limited to La Pavoni. And there's no need to upgrade the heating element since La Pavoni and other home levers do fine with steam. Commercial steam power would be too much anyway for the small shot size of a Caravel.