Use a large damper to make the simulation quasi-static.
This is a solution for finding a series of static balance forces along a change in configuration for any mechanism.
To do this you need to use a quasi-static style of analysis. If you add a large damper as shown with long simulation time duration so inertia effects are negligible, you can get the force out vs cylinder extension. This is still a dynamic analysis requiring mechanism dynamics extension.
A constant force motor was applied at the cylinder and the net load measured at the damper.
If concerned that the damper force is not pure Y direction, you could also reverse those and have a constant downward force at the output and the damper at the cylinder. Or you could just send the bottom attachment of the damper down significantly in Y.

This seems simple enough but I believe this is a better answer to several similar questions in the community and it just popped into my mind today and I thought how dumb I was not to think of this yet! 😀 Thanks for reviving this question! I have Creo 10 models if you like a model.