That wasn't clear in my post, which is why I deleted it. Anyway, I don't have the wheel; I use a computer! Would you plan a multilevel dive with the RDP?
Actually, I do sometimes use the RDP to plan a multilevel dive. A typical case is on a boat in a resort area and the DM is saying "OK, for this dive we are going to do xxx min at xx feet, then yy minutes at yy feet, and then the rest of the time above 40'.
The RDP is a good tool to do a sanity check on such a profile. My computer doesn't have a decent way of using it to pre-plan multilevel dives. It does a great job of tracking it realtime, but no way to plug in a profile ahead of time and see what it says.
In practice, the number of different multilevel profiles done with single tanks on dive boats is not all that many, and after a while I don't need to look at a table to validate a plan such as 15 @ 80', 20 at 60', then on up to 35' or so. Way too many divers, though, just sit there and accept the plan without thinking about it.
Of course, the other half of the plan is a quick calculation of whether or not it makes sense from a gas consumption perspective, but that's a different thread.
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You can also look at a proposed plan from the perspective of depth averaging. 15 minutes at 80' and then 20 minutes at 60' is 35 minutes at an average depth a bit shallower than 70'. That is close to but less than a standard NDL of 40 minutes at 70', and right at the limit of the "Min Deco" table on page 14 of the reference below.
If you want to look further into depth average and ratio deco,
http://www.txfreak.de/ratiodeco.pdf is the guideline.
DIR-diver.com - Average depth for deco? is an excellent article which helps to show what sort of profiles are valid for averaging, and discusses some possible "adjustments" for reverse profiles.
Both of those articles are primarily oriented towards dives with significant mandatory decompression and dives with minimal deco are kind of an afterthought, so it takes careful reading to see what does and does not apply to normal no-stop single tank diving.