I think that "Notably though" sufficeth in making your point, to the extent that:  

- I consider it unlikely that any intended reader would miss your point.   
   
- I doubt that few, if any,  would think its use inappropriate in the context or even feel that the term "stands" out as they read the text.

You could consider introducing an element of "... in my opinion ..." but, as your text is probably seen as an opinion in the context, "facts" stated are probably already seen as opinions. 

Perhaps something like:

   "In my opinion, X’s perception of himself as a learner is closely linked to his literacy abilities, and so I'd consider it [very] likely that these two areas will improve reciprocally."