I believe that position was a remark from an IRS representative at an ASPA conference (don't quote me but I believe it was the 2000 ASPA Annual Conference at the Grand Hyatt in DC). The remark was not an official position of the Service and is not supported by current rules. The issue of seasoned money constituting a distribution and the entire premium taxable is not supported due to the fact that no distribution has occurred. The funds, although currently accessible, are not removed, distributed, from the plan trust, simply reallocated to a pre-retirement survivor benefit, life insurance. Taxation does not occur until funds have actually been distributed from the plan trust. [IRC 402(a)]
Totally agree with the limit of 49.99%, best practice is 35% to 40%, leaving room for the cumulative test. An important note in design when dealing with a Profit Sharing Plan is the fact that Profit Sharing contributions are discretionary while insurance premiums are not (in most cases). Also agree with the taxation of the economic benefit, also known as the PS58 cost, which is taxable but it does create basis which is recouped upon distribution. And yes, subject to Benefits, Rights and Features.