Might have chanced it had shipping costs not been extortion due to COVID. Evolutionbike is covering my shipping costs due to the high order value (ordering intake valves and springs). If I realize I need a bolt or two later, it will literally cost a few hundred euro to get the new bolts to me so financially not worth the risk. My recent shipping cost to get new valve guides from the US (Bruce Meyers) was as much as the guides themselves!I'm telling you guys... if the manual does not specifically state to replace with every use then you are wasting money doing so.
As the Technical Service Manager for a Japanese manufacturer, that is what I would tell you if you called in to the technical support line to ask.
Do what you want.....it's your money
In any case, lets see once the new parts arrive. Keen to see if there is measurable strain on the old bolts.