I'm diving into the LV BOA game. I ordered some K2 Cortex 105 Zonal BOA in a 22.5. First thing I do with any boot I try on is a shell fit. This is a TRUE LV boot. As in, it's lower volume than the Lange RS 21.5 I have around my ankle and foot, but obviously allows for my poor toes to not be squished. I have had the toe box in the Lange's punched/ground to the max and my left foot (my longer foot) is still crunched, and I do believe it has added to my foot woes, which are worse in my left foot. I think I have a high pain tolerance, because I'd just ski with the discomfort (180 ish days in those boots!) I have about 2mm on either side of my foot at its widest point in the K2s, and very little room around my lower leg and ankle. The room behind my heel is not even 5mm. This makes me happy! They seem very similar in shell fit to a pair of Rossi WC boots I still have collecting dust in the closet. Race boot liners are so thin that I HAD to have an aftermarket liner for them to work for me.
The Cortex seems significantly stiffer at 105 than the Lange at 110. The 95 flex Cortex doesn't come with double BOA, and there are not many 22.5s out there. I don't love a stiffer boot in powder, hence why a 95 might be good for me. I am not sure how the 15 degree forward lean will feel. I found that the 12 degrees in the Lange felt really good.
The BOA system is going to make a LOT of low-volume foot people happy, I think. I have not maxed out the dials at all. The stock liner tongue is of concern to me because I think it might give me some shin pain like I had in the Nordica Promachine I had a few years ago. But because the tongue is removable (yesssss!!) I can always swap it for one of the plethora of aftermarket tongues I have (I have 6 different tongues, I believe.) I have two that were foamed for my leg, so those might work. The issue is that the velcro in the Cortex that holds the tongue is pretty lame, and none of the other liners I have will stick to it. Worst case, I will sew a different tongue in to hold it. We'll see how I feel being in a non short-cuff boot again. I'm just tired of being in solid sole boots that need a ton of work done on them and still have issues. My husband spent decades cramming his 28.5 foot into a 26.5 boot and his feet are a total mess of spurs and bunions. He has skied in a 27.5 for a long time now but still in LV despite not having even a remotely LV foot (I think a MV BOA boot would make him happy!) I don't want to do the same thing to my feet.
The best fit in the K2s is with the ZipFit liners I have. However, getting the boot on with the ZipFit is heinous even with a heated boot bag, and I worry about damaging my injured achilles and foot even more trying to wrangle the ZipFit in. I may try to put it on racer style using boot spray. The stock liners are remarkably snug, with the exception of my usual trouble spot from the medial malleolus forward to the front of my arch. They are not loose, but I can tell they are not going to hold me stacked very well. My ankles roll inward when I'm on skis unless I have a liner that is really firm from my arch up to my upper ankle. I have good footbeds, I'm just too loosy goosy in the ankles. I like the laces on the stock liners, too. I'll use them for sure.
I still want to try the Fischer LV BOA 105, although it is not double BOA. I am also curious to try the Atomic Hawx Ultra LV BOA just to see if either of those would fit much differently. Not easy to find 22.5s anywhere in stock, though. I think Fischer has had tariff issues or some other supply issue because some of their inventory shows it isn't anticipated in stock until January.
I am choking at the price point of the double BOA.

I can probably get the Fischer at a discount and maybe the Atomic, but I don't know any K2 skiers, here BUT if they work, they are worth the price. The truth will be known once I get on snow in them in the next month. Thankfully I am happy with my current skis so can invest more in boots this year.
My initial impressions are that BOA in a true LV boot will allow a lot of us who have been forced into solid lug race or race-inspired boots to get into non-race boots that won't need to have plates installed and aftermarket liners. No more slippery soles, either!