There is an enormous amount of:
Contemporary cello music...
written by French/French-based composers...
for specific French/French-based cellists.
Each piece, each composer, each performer uses specific stylistic features, a particular language.
But how are those features shared with other people who want to perform this music, to learn from it, to understand the creative process?
It's often hidden - too precise to be notated in an inanimate score, too unique to be quantified in writing.