What is the link between the type of plate boundary and the strength of earthquake/seismic waves? Is there a link?

The answer is; Yes, they are linked

Convergent plate boundaries have larger earthquake magnitudes compared to divergent plate boundaries. This is because, in convergent boundaries, the plates are colliding and there is a huge buildup of stress between the plates. This is unlike divergent plates that are moving away from each other, or in transform boundaries where plates are moving along each other.