I cannot figure this one out.
It is possible to inflate an object by setting rest scale up in the constraint settings.
But this only works once and very quickly dependent on the dampening.

What I wanna do is something like this, after like a second or inflate, deflate, re-inflate

You can increase the f@restlength primitive attribute on your constraints via a SOP Solver DOP or a Geometry Wrangle. Just make sure that the Data that you're editing is “ConstraintGeometry” instead of the default “Geometry”. If you're using SOPs-style Vellum, drop a Geometry Wrangle inside the Vellum Solver and connect it to the “Wire DOP Forces Here” input, set the Data to “ConstraintGeometry”, and then try something like as your VEX snippet.