The top cap of the Isolette is anodized Aluminium, and thus isolating. The cold shoe though is chromed.
(Maybe though the cold shoe of Peltigera's sample is anodized too, or he overlooked that issue.)
No, the basic function of your flash will not be damaged.
(Just let it load off the camera and then push onto the cold-shoe, it will fire.)
However, shortening those other camera dedicated contacts might induce error.
Thus set the flash to M. In the A setting it likely still is employing one of these contacts.
But so far I know of no dedicated flash where there is a warning not use it on non-dedicated cameras.
And likely those contacts are cold at the side of the flash. Have not yet looked into that...
But as I indicated, remedy is simple.
Or even better, buy a flash where plugging in a synchrocable will disactivate the hot-foot contact.