I ended up using an outside app to solve for this, Tasker and Button Mapper. I used tasker to create a task that opens an "android android.intent.action.VIEW", and Button Mapper to toggle that task with my preferred shortcut. Before creating the task I cleared my default players so the first time it ran, the shield would ask me which media player I'd like to use (and set as default).
Basically the Tasker task is as follows:
Intent Action to Open Video using "android.intent.action.VIEW" and file:///storage/emu.../0/Download/MyVideo.mp4 (there's prob another setting I'm forgetting here)
Wait Action - Set to 38 seconds
Back Button Action
Wait Action - Set to 77ms
Back Button Action
Switch Focus to Previous App Action
By default, Kodi will pause whatever video if you open another app and it loses focus, so setting up the whole task chain was pretty easy.
Edit: Another key was finding a video player that will allow you to toggle a setting to "quit" the app if you press back twice - in my case, I ended up using MX player. If you cant quit the player like this, it will just try to resume the video again if its not quit properly the next time you toggle the commercial.
Edit 2: Be mindful that if you wait too long, Android might decide to kill Kodi cause its eating up too much ram. So if you're using this strategy, try to kill as many background apps as possible if you want a longer commercial.