Use Sites.Selected Permission with FullControl rather than Write or Read
Over the past year Microsoft have released Sites.Selected permissions for both Microsoft Graph & SharePoint which can be given to an Azure AD App (App Registration). When created the app by default with Sites.Selected permissions does not have access to any SharePoint sites and has to be explicitly added added using Microsoft Graph or PnP PowerShell (Grant-PnPAzureADAppSitePermission) to the site(s) to be administered. Both processes only give the access Read or Write permissions to the site and not Full Control.