So installing Linux Mint onto an iMac was fairly simple. 2014 iMac + Linux Mint 18 burned to a USB disk via Etcher.io just boot hold down the option key and select the UEFI boot option for the USB disk. Hit e when the boot menu arrives, add nomodeset to the boot line after quiet, hit F10 and done.
Mac ran in software rendering for the install, but after, hardware support was working. Not a big deal. Grabbed the drivers for the wifi via update and everything is working. Installed Slack, and Zoom and I’ve got all my work tools lined up. Easy peasy minus Visio. I’ll just VM that.
Also have a spare Dell laptop at home that’s fairly new as well. E5440. However I had a Linux Mint 18 USB disk having used Unetbootin to make it ran into major issues. Problem turns out after 2 days and I get into the guts of what’s going on, the installer was crashing and giving me the reboot menu like everything installed correctly. Was trying to figure out why the EFI boot was not working loaded the disc up and no EFI boot, no user account either other than root. It was then I realized that the install was not completing.
Redid the USB with Etcher.io and everything was good to go.
So looks like not all USB iso burning tools are a sure thing when it comes to UEFI booting.