The main thing to check if you are switching to 50/50 coolant is the pressure cap. From memory, the Evens one is 0.8bar and the 50/50 has to be 1.2bar. Radiator cap is around £50. The LAA recommend you have a coolant temp gauge as well as cylinder head temps. Cylinder head max temps change when you change coolant.
Most of the people I know who switched to Evens switched back complaining of overheating and expense. My 192ULS has only ever used 50/50 and I have had no issues even in southern Europe in summer.
Good luck!
Rod1