Wooden worktop and upstand. So many questions....

[Stretch]

Just check the MI's for the specific gas hob make and model as they vary with their guidelines for minimum clearances. Some you will get away with 30mm but others require 50mm.

As CL says, with a H*****s worktop you will have 616mm anyway so it's probably worth bringing the cut out nearer to the front.

I once had a plumber refuse to connect a hob as the MI's stated 50mm but he measured 47mm. And that was with tiles! I did question him about how 3mm could make any possible difference and that tiles were non combustible anyway but he wasn't having any of it.

It was all I could do not to twat him!