Do you have a reason why you are prioritising gas if it is creating complications with your choice of backsplash? Only asking because for some the preference for gas is based on outdated understanding that electric is the inferior choice.

I wouldn’t trust photos online. Many are staged, renders Or photoshopped. And many are American. I wouldn’t spend $1000s on a benchtop and then go against its installation instructions (and I’m generally a rule bender).

Look at a porcelain backsplash

It is not recommended, it is the Australian standard rules. This is because the stone can heat up and is combustible.
As Kate said, Porcelain back splash or ceramic tiles are a better choice.

Or install an electric cooktop.

https://build.com.au/splashback-regulations

I have a marble splashback behind my gas stove. It’s 180mm off my rear burner. The marble is a calacatta slab, so it’s mostly white and it’s been there for 7 years so far with no signs of discolouration or damage. From what I understand about stone as a backsplash, it is reconstituted stones, like caesarstone, that are not recommended with gas stoves.

Thanks for all your comments but this is my situation at the moment hence why i asked the question… stressed to the max and not sure where to go with this.. ive already been without a kitchen since May due to another kitchen company doing a runner on us and now this!

In the information that came with your stove top, what does the manufacturer say are the install requirements?

Did you provide the cooktop? Was it installed according to its installation instructions?

I think you are probably fine. I just looked at a spec sheet for an Electrolux and a Bosch cooktop and it seems that there are no min requirements as long as the surface is non-combustible. Also the thickness of the marble slab will play a part there as min thickness required for a tile used in a backsplash is 5mm. A marble piece would easily be 12mm thick. To put your mind at ease, search up your cooktop on the manufactures website and have a look at the spec sheet.
My only problem with your layout is how do you use the rear burners on the cooktop with a big pan or pot? This looks like one of those situations where whoever designed this has met the minimum requirements but ignored functionality.

OP is your benchtop and splashback a natural stone like marble or a manufactured stone edge Ceasaratone?

If the bench top is quartz eg, caesarstone, silestone, etc etc, then I would be installing an electric induction cooktop.

If you have stud walls with quartz, and a gas cooktop, the timber studs need to be protected before the quartz was installed. If that happens now there would be no room at all for your cooktop and you require a certificate from builder/tradesperson, to verify this as been done.