[TYPO3] Howto override TS in accessibility section of css_styled_content

[Xavier Perseguers]

Hi there,

I try to override part of the definition of the menu/sitemap from 
css_styled_content in order to display the subtitle when available 
instead of the title. The TS to be modified is found in the 
accessibility section of sysext/css_styled_content/static/setup.txt

If I modify this file, my code works but if I include it in my own 
template TS (which should be applied *after* any base/extension/... TS), 
it is not taken into account.

Code

tt_content.menu.20.2.1.NO.stdWrap.field = subtitle // title

What do I have to do? I tried to enclose it into conditional blocks:

[GLOBAL]
[compatVersion = 3.9.0]
tt_content.menu.20.2.1.NO.stdWrap.field = subtitle // title
[END]

or simply

[compatVersion = 3.9.0]
tt_content.menu.20.2.1.NO.stdWrap.field = subtitle // title
[END]

But it is not taken into account!

What did I missed?

Thanks for helping
Xavier Perseguers