1. My 2 Cents said earlier: "How do you get around the ERISA/regulatory mandate that in-service withdrawals can only be made if the hardship rules are met?"
The Service has said this isn't an issue. 1.72(p)-1, Q&A 12:
"Q-12: Is a deemed distribution under section 72(p) treated as an actual distribution for purposes of the qualification requirements of section 401...?
A-12: No; thus, for example, if a participant in a money purchase plan who is an active employee has a deemed distribution under section 72(p), the plan will not be considered to have made an in-service distribution to the participant in violation of the qualification requirements applicable to money purchase plans. Similarly, the deemed distribution is not eligible to be rolled over to an eligible retirement plan and is not considered an impermissible distribution of an amount attributable to elective contributions in a section 401(k) plan. See also § 1.402(c)-2, Q&A-4(d) and § 1.401(k)-1(d)(5)(iii)."
2. As to the general issue, this has been debated forever (as can be seen by the number of topics devoted to it here). I don't have much to add to the above, except that 1.72(p)-1, Q&A 19 requires that after a default, subsequent loans must be repaid by payroll deduction pursuant to an agreement "enforceable under applicable law." However, this is conditioned on the following: "For this purpose, an arrangement will not fail to be enforceable merely because a party has the right to revoke the arrangement prospectively."