As RRP has said, wee don’t recommend aging tenderloin, though many people ignore this advice! If you really want to do it, buy the Large Chacuterie size (8 x 18 inch).
Dry aging results in more tender meat. It is most suitable for slightly “working muscle” steak cuts such as striploin or ribeye. As tenderloin is a “lazy muscle,” dry aging can result in unappetizing, almost mushy tenderness.
Also, tenderloin is a very costly cut. When you lose 20% of it to trim loss, it can feel like a waste.
If you do decide to dry age your tenderloin, you can get the deeper flavor without needing to trim it if you only age it for 5-7 days. To further enhance flavor, we have recipes on our original site for crusted tenderloin. Just be sure to keep the cut intact, without any trimming. The fat layer will be protective and flavor enhancing.
This video shows the tenderloin medallion and chateaubriand methods of preparing the long tenderloin muscle when crusted:
https://youtu.be/ltA4MoeEvlk. Hope this helps!