I don't see how a general mathematical concept could be considered a proper noun, regardless of capitalization or lack thereof. UTD doesn't have a trademark on it.
There seem to be some misunderstandings about ratio deco as a general concept. At the core it's nothing more than a recognition that a 3-D surface (total deco time as a function of depth and bottom time) can be approximated by a tangent plane within a limited area, and a 2-D curve (the ascent profile) and be approximated by a series of straight line segments. That's it. It's trivially true and just basic high school math. We can then calculate ratios to align to any underlying deco model for a narrow range of dive profiles.
Which leading deco experts are you referring to? I don't know what UTD teaches but I thought the current best practice GF was closer to 70/85? Although the guidance changes all the time so I might not be up to date on that.
World-recognized decompression physiologist and cave explorer David Doolette explains the new evidence-based findings on “deep stops,” and shares how and why he sets his own gradient factors. His recommendations may give you pause to stop (shallower).
indepthmag.com
Personally I'm skeptical that it really makes much difference for the sort of "regular" tech dives that most of us are doing. Having tried a bunch of different ascent profiles they empirically all seem to work well enough as long as you spend roughly the necessary amount of time in roughly the right depth range. Like if someone got bent using GF-Lo = 50 then switching to GF-Lo = 70 (or whatever) probably wouldn't have saved them: more likely there was some other more fundamental problem.
Where is the risk coming from? If someone isn't able to make those kind of repetitive calculations without screwing them up then they're likely to make other more serious errors in related areas like gas analysis and planning. I'm not trying to be a gatekeeper here but if someone is struggling with this then tech diving isn't the hobby for them. Dive buddies should also do the planning independently and then cross check each other to verify that they have similar numbers.
No one is using ratio deco as a
primary means of creating an ascent profile. The whole point is to use your preferred dive planning software as the primary means to calculate a reference point profile, then apply your preferred flavor of ratio deco as a
secondary means of adjusting for minor differences in depth and/or bottom time. In practice most divers have at least their reference point profiles written down in wet notes or taped to their scooter as a memory aid.
Mixed gas dive computers have become far cheaper, more reliable, and feature rich now than when various ratio deco approaches first become popular. Most of us leverage dive computers to some extent but because dives don't always go according to plan it's still necessary to be able to estimate on the fly how a minor change in the bottom profile will impact the ascent profile (and thus also gas usage). If your computer screws up due to a software defect or hardware failure or user error you need to be able to recognize when it's giving you numbers that don't make sense.
