You can test sufficient pressure yourself. Drop a lo value rizzy in the holes of your meter and measure it sitting there, or sitting on top of stabilized probes. Repeat 9 times and see how different the measurements can be, if the reading is even stable. The spring tension removes any doubt regarding surface oxides on the components. I could use smaller diameter springs and get similar results, but I had 1/4" plastic round stock so designed around that. The other idea was gluing big clip leads on wood and a popsicle stick across, but I figured there would be too much chewing on the leads.
Regarding the component under test, I need carbon composite, non-inductive resistors for RF (DC to 20 GHz) termination, 51Ω ±5%. I find that composite can drift over time, in product or sitting in parts, so I screen for ±3% and save time re-working out-of-tolerance parts. The techs are measuring on a calibrated Fluke 8060A in REL, and the numbers are easy, 49.5 to 52.5.
Mike