But I would like a working Yosemite install with Clover.
From your profile it looks like you're just trying to make HD4600 work? I just got things kinda working on Z87MX-D3H, i5-4570 and HD4600.
Before you start, read 2nd post by Lexone about iMessage_debug and copy output of the script on your working Mavericks install. I got the "contact customer care with code" dialog after running iMessage_debug.
iMessage Fix thread has a lot of info on what's actually going on with iMessage. I wonder if migrating values from Maverics would prevent iMessage lock-out.
I think Legacy means not checking the first 2 boxes of Clover installer ("Install UEFI boot only" and "install in ESP"). Just follow Tony's instructions and screenshots through steps 1,2,3. I used the HD4600 clover.config file for my USB setup drive. This allowed me to get into the installer, although without QE/CI acceleration.
Things started diverging for me in Post-Install. Here's where my differences were:
1. Step 5 - installing Clover. Yosemite will set up a logical volume for the system drive. When you do "diskutil list" (I'm assuming you have 1 drive) you'll see that disk0 has 3 partitions - EFI, Recovery and your Yosemite partition. However, you will also have a logical disk1 for your yosemite partition. Clover installer didn't understand how to install into EFI system partition from there. I chose to call "sudo diskutil cs revert <disk id of logical disk>" to revert Yosemite volume to regular. Rebooted, proceeded with install. I suppose you could let it install into /EFI, then use EFI-Mounter to mount the EFI partition and copy the folder. I haven't tried that.
2. I started with clover.config for HD4600, but acceleration wasn't working. Make a back up of that file. I walked through the steps outlined in lexone's 2nd post to set SMBIOS to iMac14,1 and fill out values for iMessage. Also with Clover Configurator, go to devices tab and on far left there's FakeID section. I replaced the value in IntelGFX field with 0x0. On Graphics tab, I had both Intel and ATI checked. Uncheck ATI. After these changes, hardware acceleration started working.
3. Enternet kext in /Volumes/EFI/EFI/CLOVER/kexts/10.10/ stopped working after I migrated Time Machine backup of my Mavericks system. Instead I used MultiBeast 7 to only install the AppleIntelE1000.
4. I used
Toleda's CloverALC script to inject fix for audio. Just ran the script and followed its prompts. Rebooted and audio settings had 3 output devices I could use. I'm using analog audio, so that was sufficient.
I'm waiting on BCM94360CD with adapter for wireless and BT. Can't comment on that yet. With any luck, they will enable Continuity features (Handoff, SMS proxy, etc)