Not sure if my experience is relevant or can help you, but when I ERed and left my job in late 2008, I had to liquidate my 401(k) because it included company stock. Part of my 401(k) included after-tax contributions I made in the mid-1990s before the Roth IRA was invented which I was able to specifically separate out and take as cash (even though I was well under are 59.5). Had I still been working there, I would not have been able to do this, being able to only take out a prorated amount of principal and earnings, the former not taxable and not subject to penalties and the latter taxable along with any penalties.
As a result, the money I took out of the 401(k) as cash was taxed either not at all or very little while the pretax dollars and all earnings on the pretax and after-tax contributions was rolled over into my own TIRA.