I was a member of online "survivalist" forums a decade ago and baby chick constipation was occasionally discussed. I was thinking that the corn-based feed usually used in brooders might be difficult for chicks to digest sometimes.
In my experience, that is not the case.
I have raised hundreds of chicks on the typical corn-based chick starters.
Pasty butt has been almost completely a non-issue.
I have never had a chick die of pasty butt.
I've never seen anything close to the pasty butt photos that sometimes get posted.
For any batch of 12-25 chicks, I would typically expect to pick a bit of dried poop off a few butts in the early days, but not many. Most of the chicks have no trouble at all, and the remaining few are fine after getting it picked off a time or two. Just look at the chicks each day, and if there's any poop stuck to the butt fluff, pick up the chick and pull off that little bit-- it may take a small amount of fuzz too, but the whole thing is over in a few seconds and the chick is fine again. No enormous mess of accumulated poop, no long times spent soaking and scrubbing a chick's butt, no stressed chick from the time spent soaking and scrubbing and maybe getting chilled.
I am thinking that a more traditional diet based on foraging as chickens are meant to do might be healthier for the chicks and also get them acclimated to the conditions they will experience as adults. Also, sometimes the babies will try to eat the wood scratch in their brooder.
I would use the bin right side up, with a heat source until the chicks no longer need it, and give the chicks a shovelful of dirt or a clump of sod each day for the first few weeks. Transitioning them to outdoors at that point is no big deal.
Yes, they certainly will try to eat bits of wood shavings in their brooder. They will also try to eat the sides of the brooder, their own toes, the eyes of the other chicks, the food and water, maybe your fingers, and everything else they see. It's how chicks learn about the world. Trying to eat wood shavings will not hurt them any more than trying to eat the dirt on the ground-- either one can be a problem if a particular chick overdoes it, but most chicks figure out that it's not good food, and have no trouble. Putting down a layer of paper towels for the first day or two can make it easier for them to recognize the food (fewer options for what to peck), regardless of whether you will be putting them on shavings or ground after that.
Then there is heat. I have come across low wattage brooder heaters on occasion online while searching for other things. That will definitely require more research.
Some of the low wattage brooder heaters are meant to be used inside a warm area (50+ degrees), while higher wattage things (like 250 watt heat lamp bulbs) are better for cold areas (often including outdoors in early spring.)
If the chicks are directly on the cold ground, they will get chilled faster and more easily than if they are on a warm or insulating surface. So a layer of bedding, or setting up the heat a day or two early to pre-warm the ground in the right place, might make a big difference in how well the chicks do.