Several incidents where reported where Turbotax was instructed by the IRS to withhold portions of Individuals returns to satisfy an IRS proclamation.
Nope, that does not happen. That would be illegal. Where did you see this? Link?
See this IRS Tax Topic for reduced refunds - https://www.irs.gov/taxtopics/tc203
Turbotax can't. it's the US Treasury that retains some or all of your refund if there is a legal offset in effect.
if your refund is withheld, you authorized Tuyrbotax to take it fees from an alternative source.
https://www.fiscal.treasury.gov/tax-refund-offset.html