With a decent crimper I'd trust those more than choc-blocks (even the good ones with the metal bit between the cable and the screw). If they're good enough for automotive 12V they should be fine for mains. Make sure it's the right size crimp for the cable diameter.
Agree that Wago connectors are lovely.
The main rule with fixed mains wiring is that such connections should be accessible for inspection, not buried under plaster or whatever.