1. Bought the sizing rings and am wondering if you can wear them for maybe a full day comfortably, to better make sure the correct size.
Sure... they work like your base ring is going to and when it fits, you'll forget it is there. If it is too small, you'll know it is time to remove it.
2. Is there any difference between a single or double base ring aside from aesthetics?
Single is for most guys. Double is for those who have low hanging testicles or simply need more skin taken up by the base ring to fit comfortably. I'm high and tight so I wouldn't be able to close the cage and be comfortable with a double ring.
3. The "punishment" pins, if it's small enough and smooth is it possible to use it as a teasing implement?
No experience with these but most of the accounts that I've read are mixed. If you mount them in the cage and he gets used to wearing them, they'll lose their novelty pretty quickly as a tease.
4. Are there any measuring tips you might offer?
Sizing rings for sure (good for you), make sure you cannot get fingers under the sizing ring - only one finger and only to the first joint, no more. Measure in the morning, measure at lunch and measure at night. Flaccid numbers should be averaged and then length should be reduced by at least a quarter of an inch. Most people buy too large and have to ship it back for adjustments (myself included). The diameter of the cage is going to be super important to get right since you don't want any lateral movement. Mistress MM says should fit LIKE A GLOVE.
5. For long term wear, how well does the screw lock work?
Lots of threads about this working and not working but can be better with some Loctite from the local hardware store. A downside is getting the screw lined up when closing it after some play, can be tricky. I prefer the simple padlock but that's me.
6. Does wearing a chastity device lengthen the sack? If so, is it the constant taking on and off or constant wear that stretches the skin?
Nah. Five years in and all dimensions are still the same. I will say your body does adjust slightly to the cage being there over time but nothing dramatic.
7. He is "cut" but I enjoy gently grinding, and am looking at inversing the front bars. Would this give any sort of con for his wearing it?
MM does this most of the time for men that are uncut and find the stock configuration uncomfortable. I don't think it would present any issue.
8. If you have experienced both cages, which do you prefer and why?
Can't help with this one.
9. We've tried the Holy Trainer v3, he found it too bulky. Is Mature Metal slimmer? I'm assuming so by the pictures, but looks can be misleading and we all know what it means to assume.
Proper fit is key. Custom cage means you can size it as you see fit but it needs to match the anatomy. Slimmer? No. I would suggest a proper fitting custom cage is going to stand out much less than a "one size fits most" from the shelf.
Final thought... listen to MM carefully and do as they suggest. They know what they are doing and I have learned to trust their counsel whenever it is offered.
Spend time and listen to Lady M and Caged Monkey interview William and Mistress MM on their podcast. Great information in among all that laughing.
http://monkeyinacage.fetblogger.com/pod ... ure-metal/