If you prefer it with the 26 inch wheels then ride it like that!
As you’ve found out though you’ve dropped the BB and may get pedal strikes but you’ll learn to ride around that.
The wheel size shouldn’t make any difference to angles and slackness, the static angles stay the same even if you put BMX wheels on it, you only get a slacker feeling by running more sag at the rear or by putting one of the bigger wheels on the front.
It sounds like you’re enjoying the feeling of being sat ‘in’ a long low bike and have lost that by putting the 650b wheels on it.
I’m pretty sure Brant chipped in on a thread a few years ago when 650b was just coming through and somebody asked him about running 26 inch wheels in the 45650b, he didn’t see a problem other than what you’ve already mentioned re. the BB being very low….I’m sure most designers of most AM/enduro type bikes have experimented with really low BBs for the ‘railing the corners’ feeling you describe and incredible stability but in practical terms to put a bike on the market like that knowing people are going to be smashing pedals and hitting stuff on technical climbs etc just isn’t appropriate.
I disliked my 650b HT for similar reasons and have gone back to 26 inch wheels there but still run a 650b full-suss and like how that feels….I suspect you wouldn’t have minded if you hadn’t tried the smaller wheels first!
You could always run the bike with more sag at the rear and an angleset on the front to further push the forks out and get the bike sitting lower on the bigger wheels?….that’s what I’d do, I wouldn’t sell that frame as it’s just too good looking!….easily the best looking full-suss out there right now and I know that shouldn’t matter but in the case of the Commencal most reviews praise the ride too so you’ve got the complete package of looks and performance!