Which instructions? I just pulled this from 2016 5500-EZ instructions.
Who Does Not Have To File Form 5500-EZ
You do not have to file Form 5500-EZ for the 2016 plan year for a one-participant plan if the total of the plan's assets and the assets of all other one-participant plans maintained by the employer at the end of the 2016 plan year does not exceed $250,000, unless 2016 is the final plan year of the plan. For more information on final plan years, see Final Return later.
Clearly you have to file for the CBP. And if these are not owner-only plans it doesn't matter what the assets are, you have a filing requirement.