+1 – exactly the same story here.I use thick silicone gaskets on the rocker box's with no reinforcement, never had any leaks before but now do not have to replace them as I did before with normal gaskets. They are from before JS did theirs but if I wanted to replacements then I would go the JS route as the ones I have do suffer from being too soft and you have to be careful and not overtighten or they spread out too much.
The stock paper gaskets sourced from Old Britts have worked well for me. A thin smear of Hylomar on areas that don't need to be accessed and a thin layer of bearing grease when I know that I'll be needing to have a frequent look see. Valve covers get the grease treatment and I've never had an issue with the oil getting out. Maybe I should try grease to help keep the smoke in on my few remaining Lucas components