How useful it is going to be, I don't know. However, Divine Might Holy Spirit takes precedence over Requiescat Holy Spirit. This means, if you go into Req with Divine Might, you can, mid blade combo, use Holy Spirit, which uses up Divine Might but will NOT consume a Req stack and continue with the blade combo eg.

Req (DM/4) > Confiteor (DM/3) > Blade of Faith (DM/2) > Holy Spirit (2) > Blade of Truth (1) > Blade of Valor (0)

Atonement still breaks the combo.

The more you look, the more you can see flexibility, however, knowing that it is all still confined to the FoF cooldown, so you cannot go into it however you want, is really going to stifle that flexibility.