Platform with passive "weight-bearing" element to take some load off motors/actuators

I'm just starting to think about building a DIY motion platform, and I'd like to see if I can come up with an idea or two to incrementally improve on the great work that everyone here has already done. I'd like to do more than a 2DOF seat mover, but don't think I'll go all the way to a 6DOF Stewart platform for my first build.
One concept that's intriguing is some kind of passive weight-bearing element that can support most of the platform's weight, leaving the motors to primarily drive movement rather than holding up several hundred pounds of weight. The 2DOF seat movers have long leveraged this concept by placing the pivot (universal joint) at or near the center of gravity. Kinemaniacs/Ark Dynamics have a patent on a 6DOF Stewart platform that includes pneumatic cylinders bearing the weight, so they can get away with using smaller hoverboard motors. I haven't seen the concept applied to 3-4DOF systems although I might just not be familiar with all of the work people have done.
It seems like a good idea, but maybe I'm missing something... are there any disadvantages to adding a weight-bearing element to a platform, to reduce the load on motors? Obviously cost could be a factor, but it seems plausible that the added cost could be offset by being able to use smaller/cheaper motors. (Or better performance from the same motors)

That's a clever solution. It seems to me that with the right spring rate (perhaps by using an adjustable-rate spring), this could actually make the motion feel more authentic since it would mimic a car's suspension.
As a variation of your idea, I've seen some people put their entire rig on springs to get better effects out of a bass shaker. Maybe one of those springs, with the

Gas lifts are one of the solutions - they have a constant force regardless of the position of the rod (except for 2 cases), so they are ideal for compensating for the player's weight.

springs work - but are not suitable for everyone's weight

I saw a sim some years ago that used leaf springs to assist heave !

I tried some gas struts years ago but found they dampened the small movements

adjustable air bags/pistons may be a solution to suit a range of weights

at the end of the day - more powerful motors can not be beaten

That is what ansible does.
https://patents.google.com/patent/GB2602351B/en?oq=GB+2602351+B

Be careful with this line of thinking. The data from the game will give you the details of the car. The sim is just a delivery system for that data. You don't want your delivery system to change the data going into your body.

Think of it like a hifi speaker system. You design the drivers in the speakers to represent the frequencies exactly. Anything else is not delivering the true experience.

Seems a bit odd they have applied for a patent on something that anybody could design

I bet somebody has tried to patent the wheel !

All interesting ideas. Agree a pneumatic system should do better than a spring in terms of maintaining a near-constant force, assuming the pneumatic system is large enough so the internal air pressure doesn't change substantially as the piston moves in and out. Even so, you would probably want a way to adjust the air pressure as needed, at added cost and complexity. You guys may be right that using more powerful motors is the better solution at the end of the day.
Other possible ideas would be some kind of counterweight system, putting the platform on rails (like the yaw chair), or mounted on pivots (as in a joyrider). These all have limitations that may not be worth the effort.

I used to have a link (several year ago) to a French guy's website. His system used cables and rails for a flight simulator. It had a seat that rolled on a pair of semi-circular rails for roll that was driven by a cable attached to a single motor. This assemble was mounted on another pair of pitch rails driven the same way. Not sure if his website is still up though. Maybe someone here might know who I'm talking about.