I love my Lyn. Now that I’ve played with a celcon plastic (which is what the Lyn is made of) for so long I don’t think I could go to another kind of plastic. I just love the solid, more weighty feel it has compared to the hollow, cheap feel of many other plastics. Mine has a center trac bearing and I siliconed the grooves where the o-rings used to be. It’s just where I want it, long spinning, dead unresponsive and has nice tight binds. It’s my main throw right now but I’m just getting to know my two new metals (YYF DV888, Kyo DNS) both of which are less than a month old so that may change but I know my Lyn will still always get regular play.
Just my 2 cents, skip the shims and play it as it is. It’s a great yoyo and for me, the perfect weight. If it’s too responsive, clean the bearing or sub-out a loved bearing of your choice. If you think the gap is too small, take out the o-rings and silicone the grooves. It doesn’t really need a wider gap.