Advice on corners for subway tiles please. - Tile Advice

[NeatOne]

Hi, I am in the process of tiling with subways and just wanted some help with corners, if trim or grout is best? Am tiling in wetroom on backer board, Wedi tray all sealed in. I started tiling floor to ceiling and just thinking about the corners. I have one 90° internal corner (which I have tiled up to) and then about 35cm from that the wall is angled around 160°. So two corners quite close together. I had planned to use grey tile grout but wonder if this will look wrong with off white tiles it will give the appearance of two dark verticle lines quite close together? I think that Schluter have an angle trim for 135° and wondered if this could be used on the 160° angle or if anyone has any suggestions. I did subways 20 years ago in the bathroom and kept the tile gaps small on the cut tiles and used a grout to match the cut tiles and on the whole tiles left the gap consistent with the wall and used a grey grout. I understand that epoxy grout is best in wetroom situations so would not be able two different coloured grouts as I have done in the past on the corners. Have underfloor heating to go down with porcelain mosaic tiles as I believe it's easier tiling into shower area with these but wondered if Tilemaster 3000 is a good alternative to epoxy? I would be grateful for any thouhts, I am a DIYer having grown up in the building trade and can turn my hands to most jobs! Thankyou

 

[Dave]

Mitre the tiles for best finish

 

[NeatOne]

Mitre the tiles for best finish

Thanks Dave for your help, I had guessed that would be best. I will have to look into how to do it. I wondered about using epoxy to fill the mitred joints on the tiles to match the tiles (and the use a darker epoxy grout for the joints) I'm not sure if you can use it epoxy on verticle joints, I have seen a few on you tube on steps but the epoxy is very runny and would run out on verticle tiles and end up in one sludgy mess?