Nationwide power limits, by any metric, are not one of the rule proposals listed above for this year.
An ex-SCCA & current NASA official emailed me this on that question:
Grand Am and AMA Pro Racing (both part of NASCAR/Daytona Motorsports Group) have a bigger budget than we do (as we have no budget!) and they rely on dyno's, not data aq. That is all the argument one should need to make. SCCA has been using various types of data aq since the late 80's (specifically engine gathering data aq, installed on the Peugeot as early as 1988 by officials much the same as happens now with us and SCCA) and they still rely on dyno numbers, not data aq.
I am OK with either of the listed options above, and am waiting for the "vote" to come in before anything is decided...