I could see its benefit and I decided to approach this by tampering with the windows registry to create my context menu. Everything started off smoothly and I was wondering why people even bother writing COM just to right this simple extension to the operating system. about 16-20 items into my registry hack I found out.

There is an undocumented restriction to how many items you can have in place on the context menu. At least I think it is undocumented. Having searched through MSDN, stackoverflow and other google-bits I could not find any substantial reference that would discuss this. On MSDN there are bits discussing other limits such as 16 files or on Stack overflow I found one other being in the world who knew at some point in 2014 what I know now. Alas, the question is still unanswered.

Conclusion: if you need proper limit-less shell extension, you need COM!