I play around with HLPlanner, which is free deco software, and found much the same thing.
More strikingly, if you put in profiles where you are within the NDL on the US Navy tables, it still can have you doing up on 13 minutes of deco! I put it down to "nominal conservatism" being a relative thing.
There has been a lot of windage about USN tables.
It usually ends up in a cheerleading session between at least two sides.
If you are going to approach decompression diving with USN tables, you should do so slowly and gradually, to validate for yourself and for your specific body type, whether those tables work for you, here defined as no clinical or sub-clinical symptoms of DCS.
You will be able to tell based on how miserable you feel afterwards. And if you test it in small enough steps, then it should not injure you (all bets off, however).
In your case, regarding air diving to 130 ft, you would first do a simple and slow bounce dive, down and back again, with some kind of safety stop. That should be fine, but if it turns out that you have a PFO you don't know about, it may become a major problem for you. You should definitely use some kind of safety stop procedure though, even though your USN does not prescribe it. This kind of dive represents the worst level of quasi-inert N2 levels with absolutely no gradient advantages during the deco phase. And that is probably why VPM gives such high "deco" times for many a USN "NDL" dive.
Then the next time you dive under similar conditions, stay for 1/2 of the NDL time. See how that feels.
Then after that, the full USN NDL time. See how that feels. I am assuming minimum surface intervals of at least a day, here, for you. If you feel like a truck hit you afterwards, that may be a clue that USN NDL time is really omitted deco in the real world. My money is on your getting a hit, at this level, however. I would bet that it is more likely than not. Especially if you have not adopted some kind of safety-stop procedure, or if the safety stop you do use is inadequate.
Then if all of the above were ok for you, start with a dive having 5 mins of time in excess of NDL, and see how you feel after the prescribed air deco. This of course assumes that you are already deco trained, which I find to be unlikely, or else you probably would not be considering or comparing air dives like this together with air for deco. But if you were deco trained, that would be the next thing to do.
The next step would be on another day with 10 mins in excess of NDL. See how that feels.
Gradually you would build up to a dive time needed for whatever reason you are doing these air dives with air deco.
This is called "ramping up," and it is taught as an SOP by many tech agencies, though not by all of them.
Most trained deco divers would dive to 130 ft with nitrox or trimix (called by various other catchy names as well).
Until you do all that, you really won't be able to satisfactorily judge what "nominal conservatism" really means.
