Drip tray. Air flow. Ribs

Planning my 3rd cook ever. Classic 2. What are thoughts on drip trays and air flow? Pictured are ribs with 2 options. 16" and 14" tray.

16" covers full length of ribs. 14" does not. My second cook was pork butt and I used the 16" but I was unsure if it was impeding air flow. My grate temp thermometer was consistently below dome temp thermometer. At least 30 degrees.

Should I use smaller drip tray? Cut the ribs? Or am I doing something else wrong?

Edit. Based on the comments I guess I should have asked for rib cooking recipes/details.