I'll leave out the math and other brain-twisting bits, it's unnecessary for this venue and presenting the idea is sufficient.

Conventional rocketry and attendant engines continues to advance and payloads-to-orbit continue to grow in size while decreasing in cost-per-kilogram.

However, there's a way to enhance existing rocket engine technology for greater efficiency as well as power to further boost payload capacity and lower cost-per-kilogram.

Burning gasses, even those found in a candleflame, are in fact a very low-level plasma.
Capitalizing upon this it's a simple matter to augment this with electrical energy input or microwave energy of the proper frequencies into the combustion zone and/or just after it to drive the plasma levels higher.
This by itself would increase thrust, but it is only the first step.

Now that the exhaust gasses are ionized to higher levels, you have a plasma-drive which is more efficient that what can be achieved through basic combustion alone.

Now comes the true enhancement via MagBeam technology.
The two pictures below show the results from Early-Stage tests and things are considerably more advanced now.

With re-usable launch vehicles and their attendant engines such as those of SpaceX, reducing wear on components is also a cost-issue and with the narrowed thrust jet the wear and stresses on the exhaust cone of any fuel-burning rocket engine employing this technology would obviously be reduced considerably as the thrust jet is narrowed and has vastly-reduced less contact with the nozzle.

As it uses fuel much more efficiently, fuel-mass can be reduced while still retaining greater-than-conventional payload masses due to the enhanced thrust power and the reduced fuel-mass opens additional payload-mass to be utilized.

PLEASE NOTE; As I stated, I am merely presenting the Principle Idea, and leaving aside all the finer points of engineering and math to keep this article brief and easy-to-read/comprehend.

Thank-you for your time and interest in this. I do appreciate it.