Callout inprecision

From: barney_cordoba@yahoo.com <barney_cordoba_at_yahoo.com>
Date: Tue, 27 Feb 2024 19:34:18 UTC
Testing callout precision, I'm getting consistent 5-6% error no matter which of the fancy flags and precision settings used.  Hardware clock, soft clock,  on idle cpus. absolute binary time. Same results.
Anyone ever done any testing on these functions or were they just accepted on faith? 'I expect a bit of flutter but not as much as I'm seeing.