bartenderstoneware why you don't want your home associated with IMEI when you using your phone wifi-only?
The reason is to have the flexibility @rustybird mentioned. The phone is wifi-only at my home location but I want the ability to use a cell connection at remote locations if needed without associating that cell identity with my home location. Doing this perfectly is probably impossible because data may be leaked in other ways such as usage patterns but avoiding IMEI leaks is the most obvious part.
If your phone is used 100% as a wifi-only device after installing GrapheneOS, then it should be insignificant if your IMEI was previously leaked.