I think, that it is not very useful, to generate more C-states, then a desktop cpu by given specs has. The values should be correctly recognized by Pike´s ssdtPreGen script or by Clover. Look at the data sheets at intel for the values of your cpu. Mobile cpus have for sure more states to extened the time of usage with battery power.
More important is to use the correct SMBios for the platform of your cpu architecture and fake a not existing mac model based on this personality, but you have to exclude the not matching cpu management parts and add a to your used gfx-card corresponding AGPM control part.
I know, that this is a bit old school, but worth every cent. You don´t need to touch orignal system kexts on every update and edit them again. If you have got your Legacy kexts working, you can use them as long as the used original SMBios personality is supported on OSX systems.
I have added example kexts for faking a not existing MacPro 5,2, based on the SMBios of an iMac 12,2 with the graphics control ID of the SMBios of MacPro 5,1. If you want to try them, you have to reinstall the untouched versions of the AGPM and the IOPlatformFamily.kext. You have also to rename your SMBios product name to MacPro 5,2, but generate your SN for the real iMac 12,2. (or edit the plists of the attached kexts to your preffered fake name)
In the attachment are versions for NVidia gfx-cards on desktop systems with Sandybridge CPU`s. You have only to edit the LegacyAGPM.kext with your ID by exchanging the xxxx digits with it. If you have gfx-performance leaks, you can adapt the Treshold values.
For AMD cards you have to edit the LegacyAGPM.kext with your Vendor and Device ID´s and the til now used values without changing the control ID.
I personally have made the experience, that it is for Clover a basic requirement to get AGPM working, having generated a valid Board SN for the used and by Clover recognized real SMBios personality.
I think more or less C-states, don´t really matter on a desktop system. More important is to have a smooth and stable running system without being suffered from KP with full and proper working PM. The lowest and highest C-states should get available reached, when needed.
For other used SMBios personalities you can for sure adapt the attached kexts.