Have you tried out this new feature yet? Have you found any good use case for it?

I'm thrilled they added custom channel groupings. Here's my use case: for some reason Google hasn't taken into account short URLs or QR codes placed on print pieces. "Print" is a common medium (at least for me) and now it can be its own channel rather than getting relegated to "Unassigned". I am disappointed, however, that custom channel groupings can't be imported/connected as a dimension in Looker Studio. Creating them manually by adding a field and then writing a CASE statement is a big hassle.

This was one of the features I missed most from UA. Now they need to allow us to use our custom channel groupings in the Conversion Paths report. Such a massive amount of our traffic and conversions get attributed to Organic Search, because that's how people get to our website when they finally decide they're ready to convert. The Conversion Paths report is useful for reverse engineering those conversions to see what other channels helped drive them to us. But it would be nice to be able to analyze the channel groupings as we define them, not as Google defines them. I would love to be able to once again create custom attribution models, but it looks like we're being forced into using GA4's Data Driven Attribution model, and who knows how that works. Being able to build a custom model based on the needs of your business would be ideal.

Finally, they’ve released a feature that can actually be applied to retrospective data. Half of these types of features are useless because they cause a split in the data. This actually seems useful, particularly as GA4’s attempts at categorising traffic is pretty hit and miss so far.

Thanks, so helpful. I have a doubt. this setup only works using medium? can I use source or it's not recommended?

I don’t see Channel Groups under Data Settings, but I see it on my other GA4 accounts. Do you need to enable?