Hi fsedano,
All CDU screen outputs are already available as custom datarefs. (like ixeg/733/FMC/cdu1D_line1L_t and ixeg/733/FMC/cdu1D_line1L_d) The _t is the smaller "title" line and _d is the larger detailed line. Co-pilot CDU is cdu2D... there are separate datarefs for scratchpad, page number and title lines as well as the CDU annunciators. (MSG, OFST and FAIL)
Pretty much all you need to build your own "virtual CDU".
Let me know if you need the complete list... (yes, I made my own)
Here's a screenshot from my Android tablet virtual CDU... still very much work in progress.