I'm pretty sure that's normal. My board edges start to look like that after only a couple runs, let alone after 8 hours. (...and I've got a white base on my Arbor,.. so that Black base is probably noticeably worse, sooner!)
Once that cloudy, dried out strip along my edges, is more than an inch or two wide, or larger patches start showing up in the center of the base, then I worry about needing another wax job!
(BTW, did my very first DIY wax on my new Rome GR. I thought I did a pretty crappy job of it, used WAY too much wax, shitty scrape & buff job and all! But it rode GREAT last night at the local!!! Fast as shit compared to fresh out the wrapper!!)