I have learned enough reading here to commit to an insert that should balance various wishes and is code happy without fuss. Getting some light work done on the fireplace, installing a mantle shield and then someone else will do the rest to install a Neo 2.5! The shop was a bit cautious as they’ve had a few customers fireplaces not be large enough - our lower level fireplace has room to spare, assuming the manual is correct. Really, really!!, appreciate all I’ve read here. Looking forward to having new questions to deal with but pretty sure the answers are likely already here.