You could do this, and it would indeed give you more flexibility in how the resulting preview is displayed on the dashboard. However, there are two drawbacks. One is that the edit mode will always show a list of slides on the side, which reduces the available area for editing the slide inline. (There are clever ways around this, but that’s another blog post…)
The other drawback is that if using multiple slides the user can advance slides by clicking in that area (intentionally or accidentally) and cause the commentary to get out of sync with the data shown. Even if you use separate files rather than slides in the same file, there is also a bottom border that would need to be creatively covered, as there doesn’t seem to be a URL parameter to hide it.
Another option one could explore is similarly embedding Google Sheets.  There are URL parameters that offer quite a bit of flexibility in which cells to display and how to scale the preview, but a spreadsheet is less conducive to the word processing use case here.