Support for SGR 10 - 19 m codes

[SlySven]

I code/develop for a different MUD Client which is also a GUI one and I was looking to include support for the 10 - 19 SGR ("Set Graphics Rendition") codes (<ESC> + [ ... m, primary + up to 9 Alternate ones).

However there does not appear to be an obvious way to specify what those fonts are. I was considering an <OSC> "Operating System Command" (<ESC> + ] ... <ESC> + \, where the last two bytes are the "String Terminator") approach but I was wondering whether any other clients - such as yours already support those <SGR> sequences and have a means for the Game Server to specify what they are/mean? If not - is it something that you'd want to consider and collaborate on?