Customizing Guildmaster's Guide to Ravnica Backgrounds w/ Spells

[LichPlease]

Seeing as customizing your own background is legal by the RAW, is it legal or do you suppose it will become legal to use the guild spell lists as another aspect of background customization? My assumption would be that if it is legal to use a Ravnica background (unless they are limited to Ravnica based campaigns), customizing the skill/tool proficiencies would still remain legal. This is turn should be equivalent of taking a PHB background and adding a guild spell list. Thoughts?

[Man_Over_Game]

Seeing as customizing your own background is legal by the RAW, is it legal or do you suppose it will become legal to use the guild spell lists as another aspect of background customization? My assumption would be that if it is legal to use a Ravnica background (unless they are limited to Ravnica based campaigns), customizing the skill/tool proficiencies would still remain legal. This is turn should be equivalent of taking a PHB background and adding a guild spell list. Thoughts?

I mean, the spell list is a lot more powerful than the background you'd be losing.

A good balance would be to have everyone who goes to a guild doesn't get a background, and everyone who gets a background gets a bonus feat. I'd say that'd be equally balanced between the two choices. Anything less makes the spell list far too valuable to pass up in any scenario.