I did notice your HR of allowing spellcaster to cast level 2 or lower spells as a bonus action, how would you handle a Quicken Spell for this rule?

Question I recently found critical role and already put in 200+ hours watching it so good. I did notice your house rule of allowing spellcaster to cast level 2 or lower spells as a bonus action how would you handle a sorcerers quicken spell metamagic for this rule? It would still function, though one of the two spells would need to be level 2 or lower! The quicken spell would allow them to both be Spells with an Action casting time, though! (Mirror Image + Haste in the same turn, as an example)

— Matthew Mercer (@matthewmercer) March 30, 2018

Is this open for players at level one? Or do you start that at a higher level (not that level 1’s can cast above level 1 spellslots) I include it on the Tal’Dorei Campaign Guide as a feat available at level 8, but it’s up to the DM

— Matthew Mercer (@matthewmercer) March 30, 2018