At what point do these become helpful?

Also, did anyone who uses these notice and improvement in weight transfer?

 

it's too limit weight transfer usually To stop the car from going on the bumper for instance.

 

Limiters on the front suspension restricts weight transfer.

Limiters on the engine keeps the engine from torquing over in factory style rubber engine mounts. This can have a lot of problems with transmission mounts, mechanical clutch linkage, mechanical fuel linkage, hood clearance from an air filter etc.

By chaining the engine down, you also reduce or eliminate wasted movement. Instead of the engine torque over, it will try to pull the frame upward.

Polyurethane engine mounts do a good job of controlling this movement and solid mounts eliminate it.

 

I run chains on my front end to make the car react quicker. The car shoots out instead of up then out.

 

since you state weight transfer, I am guessing you mean front suspension extension limiters, and this is when they become helpful.

or, here where they need to be shortened more

a lower horsepower car will need the extension of the front to keep the rear tires loaded, I can not tell you what that number is for your car, since every setup is different.
so I guess the answer is when you have flattened headers, or scraped rear bumper cover...