The only risk I can think of--and it's pure speculation--is that, in order to produce the extra voltage the windings may be smaller and the insulation less robust so longevity may be reduced; but I have no data whatsoever, and it's probably moot due to the way most Healeys are driven. Lucas sports coils were all the rage a while ago and I heard, anecdotally, of some failures but that's true for old car repops in general (many/most made you-know-where). I can attest that many CoP--'Coil on Plug'--components are known to fail often, esp. earlier ones. If you've seen one, they are considerably smaller than the old, single, beer can-sized coils yet have to produce as much, if not more voltage. VW had many issues when they first went to solid state ignitions, and I've replaced, so far, at least 10 of them on my 2000 Lincoln LS, which has a Jaguar 3.9L V-8. When they failed they would induce a voltage spike on the circuit to the ECU and, essentially, knock it unconscious. To be fair, the coil failures were often caused when oil leaked into the plug wells when valve cover gaskets failed on DOHC engines (which also happens fairly regularly).
ps. Thanks for the compliment, but I'm not a professional mechanic, but I was taught by a former auto shop teacher (my father). My former profession was software engineer, but I taught myself basic electronics along the way. I will say that is a cool-looking coil.