I can confirm that replacing an Apple HD with a Seagate Barracuda (equivalent to the original) works fine, at least on my a iMac 27” late 2013 with Fusion Drive.
I know there’s mixed opinions about this, but in my case I didn’t need the OWC Temperature Adapter: I can see the temperature is monitored correctly and fans work as expected.
I just needed to open the iMac, replace the old Barracuda HDD, boot from USB, rebuild the Fusion Drive from Terminal, install Mojave and copy from backup.
Do not clone the HD if you have a Fusion Drive,: to create the new Fusion both SSD and HDD will be completely erased.
Apart from that, everything was pretty much streamline
Thank you so much for this guide: it would have been impossible otherwise!!!