That probably won't help you in OSX. Two command-line options are "flac" and "ffmpeg". Occasionally I use flac; I discovered that ffmpeg likes to downsample by default, though its command line arguments can be used to avoid that. In my experience, neither "soundconverter" nor "flac" downsample by default.
I use flac for really large files, but in general if I upload a sound in flac then I get complaints about users not understanding how to use it or telling me to reupload in wav or mp3. The download number of my flac files is considerably lower than wav files.
Is there a middle ground of "1h recordings should probably be in flac or even lossy .OGG format. But 3s samples are totally fine in wav"? Id then ask where the lines should be, like for 5min recordings? x')
It is easier to lowpass things, record things dark, or high-shelf a dark recording than it is to tame those >10Khz frequencies. Better to psychoacoustically suggest those frequencies than have them be actually present, if you can. If you do this, you will have a very hard time A/B testing flac against mp3 and you will only lose the "ear tickling" frequencies - components of the sound which do nothing for the timbre or harmonic structure and which we lose the ability to hear with age anyway.
All my hardware - field recorders, media players, etc. only support wav or mp3 for recording and playback. So if I want to put someone's discography onto one of them, but it's only in FLAC, I have to mass-convert everything. For me this means making a blank Reaper project, importing the file, then re-rendering it. Perfectly doable, but still less likely to happen. To facilitate creativity, we have to make materials as accessible as possible so there are no stumbling blocks - not even easily addressed ones. Otherwise, we run the risk of destroying the enthusiasm which a user has for a project. Most users do not have a huge variety of solutions in hand like we do, so if they encounter a problem, it could be project-ending. Granted that it's not our fault others are less motivated, but that is the reality and we must give this matter some thought in order to ensure our materials are useful for them.