Below I summarize open issues (T85794#1394163) from deployment in MW1.26wmf11 in closed T85794 and further work to be done; best before wmf12.
* ##style## – obviously not yet implemented, important
* ~~##class## – not yet implemented~~
* ##id## – not yet implemented, used in URL, not only for decoration
* ~~When ##highlight## was used in GeSHi, the entire line was marked until right margin.~~
** Currently only graphical characters get background.
** Short code items are hard to find among many long lines when scrolling down.
** They should become obvious in the rightmost area again.
* ##line## was used to mark (e.g. bold) every 5th line.
I am happy with the new ##inline## parameter, which makes functionality clear, and discouraging any further usage of ##enclose## – eh, enclose what why how?
* ##inline## should avoid line breaks by <code style="white-space: nowrap"
** The code is framed, and it looks ugly to end a line with an open box and continue with an incomplete frame on next line.
** This goes for any ##<code>## in wikitext, btw.
** ##<code>## sequences are dedicated to few words, a short statement, which should always fit into one line; the current one, else next line.
** It isn’t helpful to have a line break between ##else## and ##if## when such syntax is explained.
Please discuss:
* ##highlight## might always trigger ##line## mode.
** It is hard to count lines when no line numbers are provided.
** Readers won’t complain about better orientation.
I do support T29531 which might utilize the ##id## of the entire block, wrt to attributes and HTML issues in this task.