Starting a Burger cloud kitchen in London, advice needed.

Hello, I am looking to start a cloud kitchen in London, specialising in Burgers. There are many burgers spots in London but most are average and use the same buns and same seasoning.

I have a couple of unique mixes, sauces, seasoning which I believe may give me an edge.

The area I am targeting via the delivery apps is central-ish London. My research has suggested that this area is the hotspot for deliveries and where most young professionals and white collars workers live and thus it makes sense to cater for them given the brand I am creating and price points.

For example, an average single order will be around £15.

The idea is to brand the business well on social media etc in order to expand and eventually launch a retail store and see if franchising will be an option. (Long term goal).

My question is has anyone done this?

And what are the pros and cons based on your knowledge and experience?

Also, does paying the delivery apps help get orders or is external marketing a better fit?

Looking forward to your responses.