I made a tiny PR (https://github.com/jamespetts/simutrans-pak128.britain/pull/133) to add a keyboard shortcut for the Marker List. Following the pattern of other recent List shortcuts, it's Ctrl+M.
I noticed that none of the new Lists are listed in the keyboard shortcuts help page (https://github.com/jamespetts/simutrans-extended/blob/master/simutrans/text/en/keys.txt). Is this because it's policy not to include shortcuts that are specific to one pakset, or it just that nobody has remembered to do it yet?
Thank you for that - now incorporated.
As to the help files, there is no policy to exclude keyboard shortcuts, so I rather suspect that it is for the latter reason that they have not been included.