I did build a larger copper heatsink 2,5x larger then the stock aluminium heatsink for my aca-1231 because I was not comfortable with how hot it ran and now it runs cool and nice even with trapdoor closed
Before the new heatsink it was to hot to put my finger on for more then a few seconds. But seems im a unlucky person who got heat issues with everything in my A1200, the Invivision AGA MK2 made my Lisa run so hot that the system would not be stable for more then a minute
Everyone told me it was not needed, but I like to keep my hardware cool and im planning on keeping em forever so extra cooling do never hurt.