Best waxes dont have to be in paste form. E.g- Pinnacle liquid soveran wax is one of the best on light colours.
The life of a wax doesnt depend on its form (liquid or paste). Paint sealants are usually in liquid form like klasse, wolfgang, chemical guys,etc.
Spray waxes are another thing all together. They arent built for durability but they are designed to boost the colours in between washes.
Lastly, why make buffing hard for yourself? Apply it nice and thin, out of direct sunlight and buff off as recommended by the manufacturer.
Letting the wax cake on will only make it stubborn during removal.
Tip- a light mist of detailer spray aids wax removal.
You're right about the fact that the number of washes makes a direct impact on the life of the wax coat but you can always maximise it by using good quality wax safe shampoos and top up with spray wax. Spray waxes actually form a sacrificial layer on top of the wax coat, making the wax itself last longer.

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