It's hard to keep from falling into bad habits when you give insulin to cover foods. I am not lecturing here, I am telling you from experience. I am one of the world's worst about it....I am such an "all or none" person, that sometimes it's easier for me to just not do the extra than to try to do it in moderation.
As long as you can do this in moderation, you can probably get by doing it, and not have problems. If you have overeating issues (and I do), it can get to be a real problem for you. The moderation is the hard part for me, because sometimes when I get started on the high carb stuff, I go overboard with it. Then my mindset gets to be that I've already "blown" it for the day, so why not just go ahead with it....the ups and downs that follow play hell on how you feel.
From experience, if you plan to do this, set some boundaries about how much you are going to "eat and cover for" before you get started.
Kim