First, you've chosen a very nice stretch of trail! Many of my favorite SHT places are included in your hike.
Regarding your question .... Please, please stay on the trail.
That "huge loop" closes a gap that was one of the last sections of the trail to be built north of Two Harbors. I'm not familiar with all the details but I'm reasonably sure the trail association tried long and hard to negotiate an easement through private property in the area you propose to bushwack. The owner was obviously not interested.
We're now working hard to convince a newly elected congressman to support the "Arrowhead Re-route" of the North Country Trail so that it uses the SHT and some other trails in northeastern MN. The last thing we need is an irate landowner sounding off about a bleeping hiker not respecting private land (I'm imagining he/she needing to be bleeped).
Also, while that "huge loop" is not so interesting terrain-wise, it passes two nice lakes and a couple nice riverside campsites, is the only place I've seen a moose on the trail and was the first place I was serenaded by wolves at night. Also, if you are going in late September the loop goes through the maple belt and this year is expected to be better than average for fall colors.
Another also, starting with the little climb to Section 13 and continuing to Silver Bay you're in what is generally considered to be the most strenuous part of the trail and the easy going from C-M park to section 13 won't be such a bad thing.