I installed my Axeos inserts at preload setting '1' as per the instructions of the day (2018). Although they are vastly superior to the stock units, being at the lighter end of the rider scale I find them a tad stiff. I now see that Legend have amended their instructions and the weight v preload setting chart, which suggests I adjust preload to '0', so I need to remove the units. Based in the UK it's difficult to buy Legend's oil directly and I'll have to use an alternative supplier. What is the recommended oil grade?