Aggregating DC for owners only with larger DB. What are the issues?

[AndyH]

Company sponsors DB plan with 45 employees covered, 8 of which are HCEs. I want to consider adding a profit sharing plan covering just 2 owners, and aggregating for 401(a)(4) and 410(B).

I've already determined that below a certain DC contribution level the general test will pass.

What other issues should be considered?

Seems to me this will not be subject to the DB/DC gateways since the combined plan is primarily db in nature (less than 1/2 of NHCEs benefit more from DC).

404 will not be a problem because the combined contribution will not approximate 25% of pay.

What about benefits, rights, and features? If the DC plan is self directed, and the only two participants are HCEs, is this a problem? Any other BRF issues?

Other issues?

This situation would be in lieu of a QSERP because I want the extra contribution to be completely discretionary.