Best practices for distinguishing events from different products?

Hi, I'm working for an edtech company. So far we had only one product that runs across web & mobile. In order to easily filter or segment events that happen in different platforms, we could use the Platform user property built into Amplitude. 

Now we are adding a second product which will launch in web first. I’m now wondering what we should do in order to be able to easily filter and segment events happening in one product. Users on both products will now have ‘Web’ as Platform.

My initial thought was to just use the data source and use that to filter. But I just checked and found that you cannot filter by source when creating a report.

So my question: What best practices do you know for this? How have you solved this problem?

I know adding suffixes to the event names of the new product could be an option, but I’m wondering if there’s a better solution (a naming convention would be great to quickly identify in which product an event occurs, but this would really also require us to retroactively update event names in the existing product – a pain I’d like to avoid if possible). Creating a custom parameter ‘product’ and adding it to all events doesn’t seem like the best idea either. We could create a custom user property ‘product’, but I don’t think it would be useful for the case when users use both products.