I'm currently playing a spellcaster who's making a lot of short dips into the lower paths, to the point that I believe I may have learned all the Free Access spells that I am actually interested in for the lowest level (for there are cheaper and better variants in the paths I have taken), if not all the spells that I could learn, from the level 1-10 Free Access spell list in the core book.
Aside from Sheeles in general and the rule on spending DP to get magical learning, this campaign has not yet touched on the Arcana Exxet, so please do not answer with subpaths; I don't want to reverse-engineer the subpath spells to work like core spells do and otherwise refuse to use them out of principle.
Leaving aside the thought of simply inventing spells to fill in the gaps, I had a thought of combining two slots of a lower level to make a slot of a higher level.
Would it be potentially unbalancing to convert two 1-10 slots into a 1-20 slot and so on? (two 1-20 to a 1-30, etc. etc.)