To date, I’ve mostly used ARA for Melodyne, VocAlign, and sometimes RePitch (alternative to Melodyne). While my reasons for using it the way I use it initially started due to stability issues with Melodyne in saved files back when I was using SONAR as my DAW, and it may possibly be that those issues no longer apply to current ARA plugins, the way I do it does avoid the huge CPR file size consideration (unless possibly temporarily).
Specifically, I’ve considered ARA extensions (beyond the three I mentioned above, I now would include SpectraLayers and WaveLab) to be similar to using a destructive audio editor, where I want the changes I’m making to be permanent. I do back up iterations of a project at various points, so, if I want to go back and “undo” a “destructive” change (e.g. if I decide down the line at some point that some tuning artifacts are too prominent after all, or if there is some glitch that I didn’t originally notice), I can always import a track from a version before the change, cut it down to just the part I need to address, and redo that part, replacing the part I’d rendered previously, but I’m generally not looking to go back and revisit those “editing” decisions far down the line. (And, when I archive a project, only the final version will be included – it is just prior to finishing a project when I keep the backups available.)
My specific workflow here is generally to only work at a clip-level (e.g. a verse or chorus if I’m tuning a vocal or tightening background vocals to a lead vocal), make all the changes for that section, then bounce the clip, replacing the original clip. (Of course, the original clip is still available in its original underlying audio file, so any backup versions of the project can access it – it’s just not in the current version of the project.) If I were doing something like unmixing a song with SpectraLayers Pro (I’ve only tried this once to date), I’d do the unmixing in ARA, copy the resulting layers to different tracks in the Cubase project, then remove the ARA extension from the original full mix track (and then disable or delete that track, depending on the specific need – the one time I used this, I was just trying to make it easier to make a chord chart for a song I was trying to learn).
I actually did try yesterday using “make extension permanent” on a WaveLab use of ARA to remove a few clicks in a vocal phrase, but it crashed Cubase (14.0.10). In that case, I would eventually have bounced that clip, along with others, into a larger clip, and the CPR file size with the ARA wasn’t much bigger than the size without it. Due to the crash, though, I ended up having to redo the change and just bounce like I usually do. (The only reason I didn’t do that upfront was because I was still working on editing fades in a comped vocal when I needed to remove the clicks, and there were still crossfades with other clips to deal with within the overall song section.)