ESC-X character string support

[Willow Liquorice]

Hello,

I've been experimenting with terminals recently and would like some 
feedback on a possible missing feature / bug / standards conformance issue.

ECMA-48 defines a "Start of String" escape sequence (refer to section 
8.3.128) which behaves very much like an OSC, DCS, APC, or PM sequence. 
The version of Konsole I tested this sequence on (4:21.12.3-0ubuntu1) 
ignored it and printed what should have been part of an escape sequence 
to the screen.

Gnome Terminal, Terminator, Alacritty, and xterm implement the sequence 
and do not print the string.

Is there a specific reason for omitting SOS functionality from Konsole?

Regards,
	Willow Liquorice