15,1 iMac SSD Wear?

[LCARS]

Last year I was given a late 2014 5k iMac with the fusion drive setup. With nearly max RAM and in great shape I thought, well let's get OCLP on it and run Sequoia.

Installation went fine. The first OCLP install separated the fusion drive but I used it as normal (occasionally) for a few weeks before it began to slow down the point of being unusable, then it began freezing up. Attempt two rejoined the two drives and all was fine for a few days when suddenly the mouse would disappear, the Magic Trackpad 2 would be disconnect, the background image would sometimes fail to appear, and the machine would freeze, or freeze but keep playing music.

Apple Diagnostics finds no issues. At this point without reformatting and reinstalling everything again, I can't get it working long enough to download a program to check the SSD wear. NVRAM resets made no difference.

I'd like to use this machine but before I tear it down to replace the NVME and pull the SATA SSD, do the strange issues sound SSD-wear related? OCLP is flawless on my mid-2015 MBP. I never encountered these issues with it. I'm not familiar with iMac- is there a common issues at play?

 

[RepairManiac]

I would not pursue the SSD Wear as a culprit. I have an iMac in the shop that only has 22% Life and it's still going. Need to replace - yes!

The standard Fusion config from Apple is NVMe on logic board + proprietary Hard Drive. The factory config with SSD only is a NVME on logic NO Hard Drive. On the 27", if you replace the hard drive with either a non-Apple drive or a SSD SATA drive, you need to install an OWC thermal kit. Otherwise, the thermal sensing will be off and it will throttle the iMac (fans should be elevated at some point).
Funny thing is that the iMac 21.5" doesn't care when you change their hard drive to a SSD SATA as it senses you have installed an SSD SATA drive ignoring the HDD Sensor all together. LOL

If I was you, I'd remove / disconnect the SSD SATA and run an install on the NVME only as a test. If NOT OK, then install the latest factory-supported macOS only and retest. I know nothing of OCLP, but this is adding another layer / complexity to your system. Does it even work properly with Fusion? On another note, I've never setup Fusion on an SSD SATA + NVME, so not sure this would be a stable or a recommended setup. I'm sure there are people out there that can say if it works properly or not. IDK