Use of "of course" in technical writing

Yes, it certainly can be used in technical writing. If the statement were written without the 'of course', then the writer might think that the reader would be confused at the mention as though the statement were some new shocking interesting thing needing lots of justification. The statement still needs to be mentioned to remind the reader, but still needs to be marked with something that says that it really isn't that deep.

But its use can be abused, a place holder for hand-waving or an unjustified leap ('of course' is kind of a deflection like 'obviously' or 'it is clear that').

As to its appropriateness (when used correctly), it is probably not the best for technical documentation because the purpose of documentation is for readers who don't understand what is going on, so you never know what should be obvious to the reader. It is appropriate in more argumentative documents, but like with any sentential adverb should be used sparingly (and also because of the misuse mentioned above where it could be associated with a gap in the argument).

It depends who’s going to read it. One view of ‘of course’ is that if what follows really is ‘of course’ then it doesn’t need saying and you’re patronising your readers by using it.