Matching existing wall and ceiling texture

Geodude

We are doing some renovation work and there are a number of places where new drywall now joins existing walls or ceilings (a mix of painted plaster and drywall). The new drywall and mud were sealed with Zinnser Guardz and then primed with 123 but the textures of the new are not a particularly good match for the existing. Existing walls are not really textured in the popcorn hide a mess sense of the word, but they definitely not as smooth and are little more orange peely than the new work. I'm looking for ideas to blend things better. I've been using a 3/8" roller but I'm thinking something a little longer might make the patches and new work less obvious. I'm hoping to avoid high build primer and sanding everything. Suggestions would be welcome. Thanks!