You might get away with this on an older 20+ year old diesel, but UNDER NO CIRCUMSTANCES do it on a high pressure common rail engine. About 10 years ago I absent mindedly put 2 litres of petrol in my 2013 vauxhall. I thought if I filled the tank it would amount to 5% petrol in the diesel and it would be ok. It did run, but even after several refills with diesel, it ran rougher and fuel consumption was down by about 10-15%. Modern common rail diesel pumps run very fine tolerances and use the lubrication in the diesel to lubricate. 5% petrol was enough to damage this lubrication effect and wear the pump.
There is often lots of traffic on Land Rover forums about adding small amounts of 2-stroke Oil to diesel to help them burn cleaner. Lots appear to swear by it, but as has been said several times on here doing anything like that to a modern Common Rail Diesel with EGRs etc has to be a risk. As an aside, if using 2-stroke Oil in a Diesel, or even petrol, consider the difference between motorcycle and Marine(Outboard) grades. The marine grades are far more expensive, but formulated differently as they are designed to work with outboards that run cooler and spend long periods of time running at constant speeds using 1/2 to full throttle.
Yes I was warned not to add anything to common rail engines. The Suzuki wasn't commn rail (Renault Megane engine I believe). It was very prone to dpf fouling and I used it off-road which made that worse. I actually did it first time by accident. I put four litres of petrol in it before I realised. I brimmed it with diesel and hoped fror the best. It ran great. Went better and no sooty smoke which it was terrible for when run on regular supermarket fuel, especially after dirving slowly off-road. I mentioned it to a mate who was a very good mechanic. He told me about avoiding additives in common rail engines. He said petrol does help reduce fouling and dpf clogging because it makes it burn hotter and cleaner buut it time can wear the valve seats because it reduces the lubricating effect of the diesel. He recommended paraffin which is basically all the much more expensive dpf cleaning additive is. I learned online about the 2 T oil. But it had to be a specific grade, not any old cheap stuff. I used to add one single dose mini bottle of Stihl red chainsaw oil to every 50 L of fuel. That worked very well.
