That is an outstanding piece. I’ve always wondered why VC didn’t use all of the chronograph movements they debuted with the Harmony in other models. They had a non- tourbillon model and the automatic rattrapante (which has been used since).
There’s a few options for HAQ. Swatch brands include Longines, Certina, and a small number of models from Omega. Breitling makes fewer SuperQuartz models than in the past. The big two are probably Grand Seiko and Citizen. I’m sure there’s others too.
I think most purchases will be driven by the secondary market value of the Principia. As a watch, I have no interest. The diameter is excessive and the value isn’t there. I can’t believe they went with rubber case inserts. I wouldn’t buy the Omega Ti Planet Ocean due to this, let alone something 5x