You are in the right range. I try to limit my 1.85L to 60 or so prints; usually I am time limited in that i get to the end of storage life before the chems are otherwise exhausted.
I stumbled on a trick that I think extends used developer life.
My machine had the fancy digital first tank thermostat die; I replaced it with one that is less accurate than the analog thermostats in my tanks 2 and 3. So I moved dev to tank 2 and blix to tank 3 (after thorough scrub down with dilute toilet bowl cleaner and nylon scouring pads, and many rinses). Tank 1 runs a water prewet, that serves to rinse off a lot of the dye overcoat of the paper. So the dyes, an organic, are not as prevalent on the paper for the developer to react with and oxidize in tank 2. Less other material than paper optical forming dye tooxidize, less quickly the developer cooks off.
I have used 4 to 6 week old used developer in the machine for non critical (ie contact prints) use after having sorted them in galss jugs in the dark.
I also pre-boil then cool the r/o or distilled water for the developer working solution prior to mixing the concentrates. This drives off dissolved oxygen , which is another thing that the developer can oxidize off with.