What does the bottom of the board look like? Too tight will leave a dimple on your base where the insert is. Some topsheets are susceptible to damage if you look at them wrong. If the base is good, who cares your binding covers it. And if the base has dimples you put them on too tight. I wouldn't sweat it if your base is fine.

 

1. The best guideline I've heard for screw tightening is hand tight, plus a quarter turn. If you have a torque driver... don't crank it.
2. Most topsheets, glossy topsheets especially, get binding rash. The stress marks directly emanating from the inserts is a little concerning, I suspect you're overtightening. Dial that back.
3. My experience with my Koruas in general are a bit prone to these types of stress cracks. Unless you actually feel insert shifting, I wouldn't worry about them too much, but keep an eye on it.

 

Thanks for the advice, I'll dial it back a little when hitting the slopes this weekend.

 

One thing you can do to keep screws tight without over tightening is to put a piece of teflon tape ( plumbers tape ) the size of your baby finger nail over the holes you are using, put your binding in place and then hand thread your screws to get them going. The piece of tape simply has to cover the hole, nothing bigger. Once you have hand threaded your screws, you can now finish tightening with a screw driver using the tighten to hand tight plus a quarter turn. This should hold you secure. However, at the beginning of every year, after your first couple of runs, take the time to check your bindings. The five minutes could save you from a world of hurt.

 

The inserts and screws are all stainless steel. Stainless steel is soft, it actually can stretch and loosen up over time. Most places over-torque them because they will eventually get loose. If you do not tighten them too much, you will have to check them somewhat often because they will loosen up over time, even if you use lock-tite (the blue stuff) or teflon tape, though they both will help a lot with keeping them tight. Always better to just tighten them as kimchijajonshim suggested, and to retighten them often. Most shops don't leave them that loose because it's better to dimple the board and damage the top sheet than have a customer come back because their binding fell off because they don't care for their stuff. But not overtightening and checking them often is the best way to care for your gear.

Those dimples are the metal inserts pulling on the layers of the board enough to distort them. The damage to a top sheet weakens it and makes it more likely to crack and let water in. Which would be under your bindings so you wouldn't see it easily.

Do like kimchi said, but tighten them in a criss-cross pattern hand tight all the way around then give it the extra turn.