Lady Melo wrote:
You would not even have the advantage of heightening the sorcerer spells so until you can take breadth feat you are at a strict disadvantage and only a mild advantage much later with the breadth feat.
From what I have learned, you can heighten the spells as normal. Counting your Character's level as your Sorcerer's level. You're already at a disadvantage for having less appropriate spells, spell choices, and spell casts per day. Hampering the spell's heightening would render a multiclass Sorcerer useless at any meaningful point.