Universal Render Pipeline - increase number of dynamic lights on a single object?

At a guess I would say no (at least not trivially). A key difference between URP and the built in pipeline is in how they handle lighting - as a very simplified explanation, the built in pipeline dynamically renders lights one-at-a-time for each object, allowing for theoretically infinite amounts of per-pixel lights per-object. This method doesn't scale particularly well performance wise, especially now that modern GPUs allow for other grouped lighting methods in realtime. URP renders all lights for an object at once, which is significantly faster but has the downside of only allowing a fixed maximum number of lights that can affect a single object. In theory you can increase this number, but the amount of instances and edge cases you would need to consider to do so makes it a fairly difficult task (especially with how sparse documentation is for the SRPs).

Very interesting! Thank you for your response. I actually did find how to do it, the URP asset lets you change the maximum number of lights (it supports up to 8).