I'm seeing a lot of tampers available now with a 'three angled slope' design, This seems a bit counterintuitive to me, since it doesn't look like you can do the polish spin after tamping. Has anyone used one, and how does it work? I'm used to a normal flat surface and have tried the concave versions some years ago. There are enough of these offered that I'd ask if there might be an advantage to using one... For instance, this set has both surface types:
https://www.amazon.com/dp/B0B91YZWVY

You distribute the grounds with the sloped side and then flip it over to tamp with the flat side.

Ah, so then this one: https://www.amazon.com/gp/product/B0BL2V2Z13 is just a distributor, to even out the grounds at a certain level, then you use a separate tamper to press in place. I guess that makes sense. I'm using a WDT to break up lumps and get things pretty even so likely don't need one of these to make for better pulls... I'm in the process of converting my Reneka Viva 57mm portafilters to 58mm so I can use more standard tools and filter baskets.