They are easy to see looking at the inside of your tunnel. Yes, many sleds have heat exchangers in the tunnel that you can't drill through.
The rack will require drilling 4 holes in the sides of your tunnel to mount it. Of course, there will be a maggot discount. In my (obviously biased) opinion, it does do some things better than most/all of the other racks on the market in terms of how it carries skis, snowboards, and splitboards, but it's not going to 100% meet the needs of everyone and that's OK. My target is to make it more affordable than all of the above options. More details to come as I build out the website and finalize pricing.
One big reason I asked about drilling the tunnel is I've been working on a rack that I'm going to be offering for retail purchase this fall. The brands that I'm currently aware of are:
