This is a rather interesting Canon patent application, and it might well go into production…
Canon may be working on more APO lenses, patent application suggests
Japanese patent application 2018-49102 describes three lenses with apodization filters: 135/2, 400/2.8, and 185/3.5.
The most interesting in the bunch is the 135mm f/2. We’ll see if it comes to market any time soon.