Disabling refresh token rotation is NOT recommended. This is for security. If a refresh token is somehow leaked and used, the refresh token rotation will prevent additional compromise. If you turn off refresh token rotation, and an attacker gets a refresh token, they have a lifetime supply of access tokens.
And if you turn on rotation, you cannot disable the absolute expiration.
I do not think that changing the settings invalidates the current refresh tokens or sessions, but I haven’t tested that.
I’d just set the absolute expiration to the maximum time (1 year maybe?)
John