The problem that prosecutorial discretion will have to overcome is selective enforcement, or the perception thereof. The right wing European media is claiming this was common practice across parties. Now I don't know the truth of it, but it is a hard thought to get out of ones head, and a hard negative to prove.
wrt Le Pen, I find it noteworthy that evey English news article I have read avoids describing the actual crime [1], Which does seem more substantial than 99% of the Trump cases.
https://www.lemonde.fr/en/les-decodeurs/article/2024/09/30/w...