I state it briefly in my comment and in my first article (https://quantumwormholes.medium.com/light-speed-holds-the-key-to-understand-the-universe-83751cbcfbb1), and extensively in my second article (https://quantumwormholes.medium.com/the-universe-explained-7df2cf8ced90)

Matter is just an arrangement of different fields. The perturbations or disturbances on any field will ultimately "propagate" at the speed of light, regardless of the mediator particle being massive or massless, since all energy or information that exists in the universe "propagates", in the end, at the speed of light.

Any piece of matter is just a structure of fields, or a network of fundamental interactions.

The entangled properties we can observe for massive particles, are not "carried" by the particles, but shaped by the same fields and interactions that shape the particle's structure and properties each time. Both the particle and all its properties (including its apparent motion at less than c or its entanglement with other particles) are recreated before your eyes each time from fundamental interactions that are ultimately related by the speed of light. Everything is made up of fundamental interactions that appear to propagate at the speed of light to us, but are really instant connections between past and present spacetime coordinates complying with the light speed ratio.

Entanglement (understood as the instant simultaneity of all the events a massless quantum experiences for the spacetime interval we observe) is what drives every phenomena in the universe.

So it is not that massive particles can show entanglement under some conditions, it is that entanglement can, under some conditions, create material structures.

In the same way, entanglement is not a consequence of conservation laws, conservation laws exist and are enforced because of entanglement.