Yes
For instance, the archive of C46 squadron one of the main Caudron R4 / Letord/ R11 user were discovered only few years ago.
And for the R11, for instance, they were intensively used for reconnaissance (especially under high threat) and escort.
Only around 200 were used in combat but the number of missions they performed was very very high.
For G6 and R4, between 400 and 500 of each were used in combat between late 1916 and middle 1918 => quite a long time
Those planes are really neglected
Basically, most wwI french archives were lost in 1940, they were not destroyed as is often said, but they were confiscated by the German, then by the USSR in 1945. They are now in Russia (where they were lost again but recovered few years ago)
Given the current relations between France and Russia, they are very difficult to recover.
For new french aircraft in FE2, I have no real choice. My position is "modders do what they want and can" but I will gladly participate to the vote.
Caudron G6/R4/R11 would be more original and would introduce new game play (unlike the Dorand, which is not "very different" from existing Sopwith Strutter, Spad XI ...)
R4 was in service for the longest period, R11 the most iconic, G6 the earliest (late 1916 / 1917)