wandempa

All my Waves plugins are V10 or higher.

Mojave comes before Catalina. If you are willing to move to Catalina, then you've already gone past Mojave. Catalina is where most of your legacy plugin compatibility issues will occur, if you have old plugins, but if your plugins are up to date and still supported I'm sure you'll be fine. If you don't want to survey your software up front for compatibility, I would image your system drive, and either install Catalina on it, or install it on a copy of your system drive and bot from that to check how everything works. Once you're happy it's all good, you can commit to that system, and if not, you can easily revert back in the meantime and keep working. Thanks for the reply. In my OP, I accidentally wrote Mojave where I meant Monterey. I'm on High Sierra, and assume I should update to Mojave at a minimum. But my debate is whether I should go to Catalina to enable being able to update Logic to the current version. It would require upgrading a handful of plugins, which I am prepared to do.

Neglected to mention this in my original post, but as part of this overhaul I'm planning to update any plugins that are not 64-bit. It is just a handful of Waves plugins that are still legacy versions. Though, if I was to only upgrade from High Sierra to Mojave and stay with Logic 10.5, same questions as above, as to whether there are any additional precautions to take prior to downloading Mojave.

I'm currently running High Sierra (10.13.6) on a MacBook Pro 2017. The machine is used mostly for music production with Logic (currently 10.4.8). I've been happy here and I am typically slow to upgrade because of all the lagging compatibility issues with third-party plugins that are essential to my workflows. But I am increasingly having sessions sent to me that originated in Logic 10.5 and these sessions tend to cause havoc with my older version of Logic. I get chronic system overload messages and it is virtually impossible to work i these sessions, so I think it's finally time to move ahead at least as far as Catalina so I can get the latest version of Logic. I have files backed up and an archive of Logic 10.4.8 in the event I need to revert. But I'd love some advice about upgrading both Logic and the OS. It looks like Catalina is the most current OS that is stable and supported by all the plugins I rely on, so I don't want to go to Mojave or Big Sur yet. Any other advice? Experiences? Cautions?

Separate but related question so dropping it into this thread rather than start a new one... I have audio tracks (no midi) recorded at 87 bpm. The client didn't send the click track and I forgot to set the tempo when starting the project so it is set at 120 default bpm. When I change tempo in the project to 87 with "follow tempo" selected it slows down the audio. When I "dont' follow" it does things to the waveforms nonetheless i.e. inserts silence, splits regions etc. I want to keep the audio files exactly as they are but just change the underlying grid to the slower tempo so that I can have a click for additional overdubs. How is this done ?