Hey @Cordeos,
Passbolt does provide MFA enforcement using Password Policy (Pro) released with v3.9.0. By default, it’s always up to users to decide if they have to enable MFA or not.
Regarding the intermediate dialog when MFA is enabled, currently there is no way to bypass the Duo dialog. For other MFA providers than Duo, you can select “Remember this device for a month” checkbox when performing a MFA so that it won’t show MFA dialog for a month.