I had some time to put some resources together that might give a more correct perspective:

Not IRA but employer plan...

From: https://www.fidelity.com/learning-center/smart-money/what-happens-to-your-401k-when-you-leave-a-job

"If your 401(k) or 403(b) balance has less than $1,000 vested in it when you leave, your former employer can cash out your account or roll it into an individual retirement account (IRA)."

60 days from when the funds were received to make the rollover...

From: https://www.investopedia.com/articles/personal-finance/112315/what-happens-401k-after-you-leave-your...

"For indirect rollovers, you have 60 days to deposit the money into another 401(k) plan or IRA. If you fail to do so, the money will be taxable and you will likely face an additional 10% early withdrawal penalty."

The 20% withholding in specific cases, and making up the difference...

From: https://www.employeefiduciary.com/blog/401k-distribution-rules-frequently-asked-questions

"You can also rollover a distribution paid directly to you within 60 days. These “indirect” rollovers are rare because rollover-eligible distributions paid directly to you are subject to mandatory 20% Federal income tax withholding. That means you’ll need to use personal funds to roll over your full distribution."

All of these are applicable if it turns out this was an employer plan account 401(k) 403(b) 457, etc.

The Roth conversion is simple: if the Trad IRA rollover was not allowed, then the Roth activities are not allowed and should be undone (as should the Trad IRA). If the Trad IRA rollover is allowed, it is a rollover of those employer funds. Basis will not change and retains what it was when it was with the employer.

If the taxpayer had no basis in these funds (if all employer amounts were pre-taxed and any earnings or match were also never taxed), and if there were only these funds, or only never-taxed funds, in Trad, SIMPLE and SEP IRA, and if there were no earnings while is was sitting in the Trad IRA, then Conversion to Roth is Taxable, the same as any conversion.

There is no backdoor anywhere here.

There is no new contribution anywhere here.

All of this can be proven by the documentation.