Most mods do add more and / or "new" missions, by changing mission difficulty at bases, but of the same type as standard FL.
Some mods have brand-new mission types that don't work, e.g. stations that can't be found, or stations called Weapon Platforms and similar boo-boos.
There are some mods under development that will have entirely new mission types and messages - that is a lot of work.
Have a look at
Mod Announcements and
Downloads Section and do a bit of reading.
You can use
Forum Search as shown at the top of this page to hunt down topics on this forum.
You haven't done that even though its simple to do, and so you did not get a reply from those nasty
people out there until now...
But personally I'm usually a nice guy
(when people are nice to me
) and I hate to leave people in suspense so I thought to alleviate your anxiety.
all the best