I'm the author of the tiddlywiki-org repo Martian linked to above. I haven't updated the elisp files for 2+ years, but I use it every day. You *do* get the best of all worlds and skip the conversion overhead. Here are some observations looking back.
.tid is basically a container format, so it works as a superset of org files and any other markup files in your tiddlers directory. TW will happily organize them for you. As a result, my tiddlers are almost entirely .tid files of "type: text/org". I never figured out how to make the default content type "text/org" instead of vnd.tiddlywiki from the drop down. That got pretty annoying, but I almost always just created tid files from emacs.
The integration in TW using org-js is pretty good. Even the links are rewired so clicking a relative link will open the target tiddler, in the same way that C-c C-o in emacs loads the target file.
tiddlywiki-mode.el will auto narrow the tid file to hide the tiddlywiki headers so all you see is the org file. The file monitor in my TW fork is buggy but works. You save your .tid org file, and your browser or TiddlyDesktop will immediately auto-rerender the updated tiddler if it's loaded. tiddlywiki-mode.el turns on auto-revert-mode by default, so when you edit the tiddler from TW, emacs auto-refreshes. org-mode transclusion might work too.
I used this setup for maybe 1.5 years, then I stopped launching the TW server, even though all my notes are still .tid in text/org. This is mainly due to navigation, search, and sprawl. Let me elaborate. I use a quick key combo in emacs to create a new anonymous tiddler. Sometimes you want to write something down before you thought of a title. After a while, I have lots of these anonymous tiddlers, and they are all named "2017-01-06_23.03.11 anonymous-tiddler.tid" or something like that. TW's built in search is decent but not great, so takes a while to find the right tid, plus you can't escape using the mouse! If you have an Emacs window open, it's far more efficient to use the helm-org-rifle package -- which works perfectly well with org-syntax tid files.
This kind of solves navigation and search, and now you're almost completely in Emacs. What Emacs, and org-mode, don't bring, is organization of the sprawling files, because org-mode is still linearly organized. One odd thing about TW, is that while it provides non-linear navigation, it still uses a strictly linear presentation. The story view is still a 1-dimentional stream of cards. I couldn't find any good ways to use TW's rendering capabilities to augment the display of org-mode files. For example, I've tried messing with org-js so that it renders sections as individual panels within TW. It's a narrow solution, and still doesn't help with inter-file linearity.
One excellent plugin that helps with organizing sprawling tiddlers is TiddlyMap. It was great in the beginning, but since TiddlyMap uses node titles as node names, and now I have a lot of anonymous tiddlers, it no longer helps. So recently, I no longer run the TW native tools, even though all my files are tid files. I'm working on other methods to work with the tiddler graph data.
This got pretty long, but the takeaway is, if you're willing to put up with some hacking, and as long as you don't make lots of anonymous tiddlers, emacs + org + tiddlywiki is a terrific combo.