He’s installing the tile plumb on a non plumb wall. That’s fine. What isn’t fine is I don’t see thinset behind the tiles which makes me think he is spot setting which is a giant no no.

He is telling me he is doing the fill in on the edges last when he installs the edging. My concern is that the wall is within the bubble lines on the level, seems the gap should be the same all the way up. Now I’m going to have a 1/2” difference between the wall and tile from bottom to top.

I don’t want to screw him out of his money but I am worried this is not going to look right when finished, can’t blame the wall. My other bathroom has tile and it’s finished with bullnose but it’s the same top to bottom

There is still 1 row of tile to go so this gap is only going to grow

" He is telling me he is doing the fill in on the edges last when he installs the edging "

Wet area tiles require 100% coverage of the thinset WHEN INSTALLED, not "filled in" later, as that is he being used as tile attachment at that point. Period. Stop.

Stop as in start over???

As stated, there is inadequate mortar coverage. Please read this document on "spot bonding" from the National Tile Contractors Association. Read it thoroughly for an understanding of the problems with inadequate mortar coverage, including in a wet area. https://cdn.ymaws.com/www.tile-assn.com/resource/resmgr/pdf_files/SpotBonding6._Final_9_12_22p.pdf

I see two problems, the wall is within 1/64” over 6’ on the level, prior to tiling. No reason not to follow the wall going up. The 2nd problem is in the outer tiles. He mortared all walls and tiles appropriately until the last tile an the 2 edges front and back of tub, he left a 1/2” space, he said it was to ensure the edging lined up properly. I havent seen anyone use this technique, all videos I have seen show a full trowl on the wall and tile with the edging being installed prior to that last row of tiles being installed.

It's a complete do over unless you want it to fail in the near future and have a bigger do over then.

He may be planning on using Schluter to trim with, and has that gap so it slides in, with mortar .. if that's the case there isn't a problem doing that. Something's not right here, you say the wall is plumb (1/64), is the tile plumb? Why would he set it that far out of plumb? Are the cuts against the back wall square? or tapered?

The problem seems to be on the right wall. It seems to much mortar was used and it just got out of wack. He should have started on the back wall, which he did, then from the front of the tub to the back wall, he did opposite and ended up with a taper. I need to fix the one wall opposite the faucets. I can’t think of how to do it without removing at least 2 rows of tile.

Both are plumb but all I can think of is that since he started at the back wall, he kept it straight vertically but on the horizontal plane he just kept using too much mortar resulting in too much thickness at the front of the tub. More so at the top than the bottom. I need a way to fix this, as long as the gap is the same at the top and bottom it’s acceptable, right now there is a 1/2” difference too to bottom on that side. All I can think of is removing at least 2 rows of tile and start from the tub, replace the tiles on the 1st row and hope the 2nd row can match up to the 3rd row. The back tiles and tiles on the front side are even, the edging will work out fine as it is the same thickness top to bottom. It needs to be filled in with schluter but it should be ok. The opposite side is my issue, I don’t want a 1/2” thickness difference top to bottom, just doesn’t look right.

No, everything is not plumb and square, if you are ending up with that. You need a tile professional. The person who did that is not a tile professional, and isn't even likely to be licensed and insured.

The walls were plum prior to starting. If he would have kept the tile pressed to the wall he would have been fine. This took like 4 days, never completed. When asked about the taper going up the wall he just kept telling me the trim would hide it, needless to say, we agreed to disagree and he left me to clean up his mess. Premier Designs, you are correct with your comment on his intentions with the schluter to trim, not sure I agree that is a good practice but definitely unacceptable for the tile to be tapered as it rises. If it continued to the ceiling there would be a 1” gap.