I wouldn't do upper outer. Branches of the anterior circumflex humeral artery exist there and are avoidable if you use other approaches. Watching dye on fluoro probably prevents vascular injection, but why even take the risk?
Superior-medial is better, and more traditionally described as the fluoroscopy approach:
Technique for a glenohumeral shoulder joint injection procedure with sample fluoro images/videos, anatomy, tips, indications/contraindications, etc.
theprocedureguide.com
Also, I can't prove that it matters, but I get the sense that being superomedial also can sometimes provide you a whiff of evidence that a rotator cuff tear is present if there is upward flow of the 1cc of contrast.