Rings are great, but they are specific, a Flowers mana can be used for any spell you have in the spellbook.
IMO, mirroring the opponents mana utilization is allowing him to dictate the game, if he is a Warlock saving for Adramelech, I am supposed to hold on to my mana until then not utilizing my actions? I perceive that there is nothing wrong in spending all of your mana, each round if you want. Now there is a grain of salt in there, if you are casting out mandatory Enchantments you need to reveal costs on hand etc. In game there are very few things that have 0 mana or 5 having mana on hand that will make a big difference (other than the previously mentioned hidden Enchantments).
The point is about increasing your channeling to enable an action efficiency on spells cost a bit more than your typical channeling rate over the game. Mage Actions are your most valuable commodity in the game, having to skip a round to save enough to bring out a [mwcard=FWC01]Dwarf Kriegsbiel[/mwcard] once is ok but you get to the point very quickly where you are wasting an action to save the mana needed. I guess you could equip a Meditation Amulet for those cases but then that is yet another action needed to get this out (in a mom-BF build).