I worry that I harmed the results by mentioning that I have meditated for cognitive benefit reasons, without a way to note that it wasn't to deal with Akrasia.

If you didn't record yourself as having akrasia, this seems like it's still useful information. It can be interesting to compare "these are the things akratics try for cognitive self-improvement" and "these are the things non-akratics try for cognitive self-improvement," and the survey didn't specify to skip that section if you don't consider yourself as having serious akrasia.

If you do consider yourself as having had serious akrasia, and meditated for unrelated reasons, then I'm not sure what I would respond there, although it seems like you might have some information about whether or not meditation helps with akrasia.