I am running into a conundrum with long niche design. It will go in this space. The linear glass will go across both walls and all the way inside the niche. I am thinking of getting one of the big tiles cut and bullnosed for the bottom (and maybe top) of the niche inside.

Issues:

1. the opening is 25", the tile is just under 24". They already cut one 2x4 in the middle to make it long, but they can of course make the niche a bit shorter. Or do we leave the niche left edge a bit to the left of the grout line bellow?

2. there is a 2x4 in the corner (and another one behind it). They would have to cut that one if I want the niche to go all the way to the right edge, and make the glass on the right wall continue flush into the niche side. Would it be safe to cut two 2x4's, the one they already removed from the middle of that opening and the one in the corner? The contractor thinks it would be safe because there is another 2x4 in the corner behind this one.

If they cut that corner 2x4, then they can make the niche opening match the size of the big tile that is bellow it, the niche bottom tile would be the same size, and would match the grout line on the left.

3. If it's not safe to cut the 2nd 2x4, I would have a weird 1" -1.5" corner with glass tile, and schluter around (schluter would be on the left niche edge too). Do I keep the opening to 24" and use the entire lenght of the tile that will be bullnosed, which would then bring niche edge to the left of the grout line? Or do I shorten the niche to ~22", so that the left edge would match the grout line?

Thanks!