I note the various comments about mixing different manufacturers components, yes they might fit, yes they may work well, BUT, BS7671 536.4.203 covers this area - components must be declared suitable for that purpose by the manufacturer of the assembly. Which means ok use different components...
No need for certificate due to 24 volt feed? I am assuming that this flex feeds a transformer. The gate may well operate on 24volt, but that doesn't detract form the fact that he has run a (1mm / 1.5mm ? ) flex directly off the back of a 32amp circuit, and I might add with no grommet. I would...