I was thinking about the uses of the Sorcerer's Quickened Spell Metamagic option and came up with my own metamagic: Slowed Spell:
When you cast a spell that has a casting time of 1 bonus action, you can spend 2 sorcery points to change the casting time to 1 action for this casting.
This would allow them to cast a spell that usually requires a bonus action and then use their bonus action on something else.
I am wondering if there are balance issues that arise from this versatility. Some potential problems I thought of:
The spiritual weapon spell could make two attacks on the turn you summon it (the first from it being cast as an action and the second when you use your bonus action). However I am unsure if this is a problem as the Quicken Spell Metamagic already has the opposite effect: Spells like witch bolt can be quickened so you can activate their action effect on the turn you cast them.
The effects this would have on the War Caster feat. This new metamagic would allow you to cast spells that usually require a bonus action (and thus usually can only be cast in your own turn) to be cast as actions, qualifying them for War Caster and thus allowing them to be cast even when it is not your turn.
Other combinations, such as using Flexible Casting to make a spell slot on the same turn you cast a bonus action spell. Or casting spiritual weapon on the same turn you enter rage. Really any similar things that result from the ability to effectively have two bonus actions on a turn (though at least one must be a spell).
Note: I do not particularly care if the Sorcerery Point cost is balanced (and believe actual playtime would be the best show of that). I mostly care if having this as an option makes for some unforeseen effects.
Is this Slowed Spell Metamagic balanced?