his would require researching how ImgFlip does their coding for this feature
Nope. It really doesn't take much to make a caption generator. KnowYourMeme used to be associated with Cheezburger, which has Memebase generator, for example. For your snowclones and image macros this is more than enough. Or, like, 5 seconds in MS paint or any other photo editing software. In addition, you can find pretty much everything you need to "make" a specific meme on its entry page, as well as our collection of templates which are free to use.
but it would be a way of making this website more all-encompassing
As pleasant as that sounds on paper, KnowYourMeme isn't really intended to be "all-encompassing". You can think of it as more of a cultural reference, similar to what TvTropes is to fiction, or what Encyclopedia Dramatica is supposed to do. KYM's entries are supposed to be informative, instead of the site being a mess of newsfeed-like elements for individual items. Sites like ImgFlip and MemeGenerator allow users to "make" memes, boards like Reddit and 4chan are for sharing said content, and KnowYourMeme documents the results. You can find literally thousands of posts, entries, and comments saying the same thing: KYM does not make memes, it documents them.
You can also check out Chris Menning say exactly what I'm saying. Or any of the other old-as-the-site-itself threads for that matter.