1) Yes, technically it is a transfer. I know there is no 1099s. I never mentioned a 1099 for this action. My terminology was imprecise, but it is clear what I was referring to.
2) What I believe the OP was suggesting was a no cost one-participant plan marketed directly to end users. For example, Vanguard Individual 401k, Fidelity Self-Employed 401k, TD Ameritrade Solo 401k, etc...
None of these providers offer low cost after-tax options for small businesses let alone one-participant plans. For example, Vanguard does not offer 401k plans with their own record keeping for plans < eight (8) figures. They partner with Acensus and the minimum administrative expenses are ~$4K/year. The same is true for Fidelity and the others.
If you want a one-participant/small business plan with after-tax contributions you are going to need a TPA. You are not going to be able to use their no cost marketed plan. That is my point.
3) To take maximum advantage of Notice 2014-54 in a plan with after-tax contributions and in-service withdrawals prior to 59 1/2, the participant is going to want to make at least one rollover of contributions and earnings/year. This will require one or two Form 1099-R(s) in any year you do a rollover.
Let us not get lost in the weeds. My points to the OP were:
There was a fairly straight forward process to change providers to a no-cost one-participant plan at major financial institutions or to a lower cost TPA. I was speculating that the administrative fees charged might be less for a plan with just a single participant owner.
As far as I last knew, the mainstream providers do not offer after-tax contributions in one-participant plans they market. If someone has factual information that this has changed, I'm all ears.
Short of that, the bottom line is, the OP can have free or after-tax, but not both.
I admit I was imprecise in the details, but could we be constructive/helpful and direct the OP to a moderate cost option.