OK. Copy all mum and cat of EnterpriseS. (This is my first time today. I don't remember what I actually did.)
1. Modify registry as you used to do 2. Copy all mum and cat from EnterpriseS C:\Windows\servicing\Packages 3. Install EnterpriseS certificates 4. set original SKU key again, e.g. Core (the EnterpriseS certificates may change default key) 5. Install CU
1. Modify registry as you used to do 2. Copy all mum and cat from EnterpriseS C:\Windows\servicing\Packages 3. Install EnterpriseS certificates 4. set original SKU key again, e.g. Core (the EnterpriseS certificates may change default key) 5. Install CU P.S. Maybe Branding, Editions, and SKU mum/cat will be OK.