My understanding is that a shareholder who is not an emloyee and who owns less than 50 percent of an employer is not a disqualfied person re: an ESOP sponsored by the employer. If such person sells his shares to the ESOP can such person take a note from the ESOP and can such loan be treated similar to a loan from a disqualified person (i.e., unallocated account, share release as loan is paid off, etc.).

I'm no ESOP expert . . . But, as far as I know, your understanding is inaccurate. There are other disqualified persons who cannot loan to an ESOP or guarantee an ESOP loan without the PT exemption, such as 10% owners, directors, officers, family members of 50% owner, plan fiduciaries, etc. So, you may have an ESOP that needs PT protection, after all.

Even if you don't need the fiduciary protection, most of the ESOP rules are mandatory for any kind of ESOP (whether or not the ESOP involves a disqualified person). Maybe there's a chart somewhere that someone can post here.

I agree with Sieve on this point. In addition, the plan sponsor is a disqualified person and typically such loans do include some kind of assurance from the sponsor that they would cover the loan. See IRC Reg. 54.4975-7(b)(1)(ii).