I
Italy
ouch!!!Nicely done,
I have the pleasure to be currently in the same situation as you were. 1000mm x 1000mm x 6 mm. Today I finished a one meter mitre and afterwards ran my finger along it to take pride in my craftsmanship, only to have a fragment pop off!! I'm placing the blame on the Italians! (Made in italy). What can you do? Grab a new tile and do it again. Such is life of a tiler. 🙂
I lay the tile on my 45 degree inclined workbench, I then mitre while standing with the tile at hip level using an angle grinder. I leave about 1.0-1.5mm material from the edge standing and small imperfections I polish with a sanding disc ( 80 grit).
When tiling I have the edges come together at 45 degrees and grout so that afterwards only the front face of the tiles remains visible. A minor difference to your attached photos.
What's your setup?
Cheers