It's been done but not advisable.
Just pull the head off and do it the right way.
If you would have used an Lc cam in the first place you wouldn't be doing it twice.
Of course its "not advisable"!
How many things have been done by everyone here that was "not advisable"?
It's easy to say "Just pull the head off and do it the right way." .... THAT is a huge job to me.
Doing things the "right way" or by the book is a good concept, but I've done many things that were NOT by the "book"... like NOT torquing a bolt to factory-by-the-book specs.
We know swapping camshafts on an installed engine has been done many times without having to remove the head and re-install it.
I have no confirmed evidence that the camshaft is causing a problem, although I have my "gut" feelings based on anecdotal experiences - mine, yours, and one other guy. How many engbldr camshafts have you installed that proved to be defective, caused a lean fire, or simply would not work properly?
At this point I have too many questions and not enough answers.
Gnarls.