There are ways to have hard-coded stuff and make it work in a Genesys way, you just have to think things through a bit in a 'how can I use Genesys for this' way.
For example having a spell recipe or instruction isn't too different to having a rune or other magical object- if you have say all the ingredients for a spell or whatever else you need to cast it, you effectively have it in the same way as having a magical object, so in similar ways I think there are plenty of ways of making your desired magic work within the Genesys system.
Perhaps the way to approach it is to work out ways that Genesys determines how magic gets 'played' game dynamics wise, Genesys in combination with your constraints of your setting determine how it is acquired or made possible for players to use. Thus you can customise however you wish but still get to an end result that the Genesys system and dice determines the outcome of.