Mature Metal discussion

I’m about to place my order with Mature Metal for a Jail Bird. This will be my first real chastity device, aside from the Holy Trainer V2 which I bought but didn’t fit me well. Here are my current measurements:

Gap: 3/8” Length: 2” Diameter: 1 1/8” Ring Size: 1 1/2”

Since this is my first device and I don’t have a huge budget for adjustments, I wanted some feedback on two questions.

1. My flaccid length has consistently been around 2 1/2”. I’ve read that you should subtract 1/4 inch when using Mature Metal’s sizing guide, but other sites suggest subtracting 1/2 inch. Some measuring guides (like Pansy Tarts) even recommend going quite small. I’m leaning toward a 2” length because I don’t want it to be too large; do you think that will still be big enough?

2. Regarding the ring size: I can fit one finger up to the first knuckle, but not two fingers side-by-side. Mature Metal describes this as an ideal fit. It feels comfortable when I’m soft (without a cage), but sleeping with it on gives me a painful erection upon waking, and getting erections while awake is also somewhat uncomfortable. My balls don’t look cold or darkened, so the size seems okay there too. However, should I order a larger ring for better comfort?

This contradicts Mature Metal’s instructions quite a bit from what I’ve read in Pansy Tarts’ guide and other opinions. I’m afraid of getting a ring that is too big, but I really like the concept of a very small cage.

Any thoughts on this? Any advice or tips for someone ordering from Mature Metal would be greatly appreciated. Thanks!