I'm glad to know that you found a means to improve this issue, but it should work without going through the steps you've described.
It's really a matter of prioritizing issues that impact a large number of users versus fringe issues with low impact. I am a DDG Community Leader and it's my pleasure to do what I can to assist you with this issue.
On my Windows 10 system I did the following:
- Performed a clean install of FireFox 49.0.2 (no previous user profiles)
- Installed the RBT extension
- Imported all of the bookmarks from my primary browser (700+ bookmarks, some in folders, some at the top level).
- Moved all of my bookmarks into the RBT toolbar.
- Change Search Settings to make DDG the default search.
- Shut down and restarted Firefox
Results: When restarting FF, RBT reloaded immediately, in fact it loaded faster than about:home did.
My best guest is another extension is the root cause of the issue. I would suggest that you create a new Firefox User Profile, then replicate the steps that I listed above and see if your results emulate mine.