Is Using of Tablet and Pen instead of Mouse Legal?

For reference, as I talk I'm using this tablet, which is a pretty low-end tablet.

So I had the thought of substituting a drawing tablet and pen for a mouse as an input device. I've run a short trail run in the practice tool, and it'd be a viable control scheme given practice. Now before proceeding, I wanted to check that the control scheme wouldn't be against regulations for potential (I'd never be that good but a copy-cat might and I wouldn't want to cause problems for them) competitive play.

I looked at the Worlds rules set for 2017, and it defines legal player equipment in section 4.2 as

" 4.2.1 PC Keyboards 4.2.2 PC Mice and cord holders 4.2.3 PC Mousepads "

Then 4.2 continues, "All player-owned or team-owned equipment must be submitted to the WCE officials in advance for approval. Unapproved equipment or equipment that is suspected by the WCE officials of providing an unfair competitive advantage will not be permitted for use."

So, if we consider "Mice," by its common sense definition, tablet and pen isn't a mouse, but considering a technical definition (which is given nowhere in the document and thus I need to invent one), "an input device used to move the cursor and click the screen at the cursors location," they would be. The question would then become, do they provide an "unfair advantage" and I would argue that they do not in the same way that 16-button mice aren't an unfair advantage over the players that would use 2 or 5-button. Unfair advantage (in regards to equipment) is also undefined, so I assume it'd mean "custom-built equipment not commercially available or equipment that tool assists player inputs."

From my short amount of testing, the tablet does allow for faster inputs than my mouse, both moving the cursor more quickly, smoothly, and variable than my mouse (set to an average sensitivity) and in terms of possible M1 clicks per second. M2 clicks on my pen do cause the cursor to shake a little, which did cause me to miss a few skill shots while practicing; but, given practice, this could likely be mitigated with better hand posture or could be factored into a person's play rhythm. While it would be a potential advantage over a standard mouse, I don't believe that advantage would be "unfair," given my definition (since the world's doc doesn't have one, probably intentionally).

So That's a lot of preface for the short question: Is a tablet and pen a legal cursor-input device for competitive play.