This product allows you to push the seal in too deep due to the outside diameter being to small. Other seal tool stop the seal flush with the fork body, because the OD is wider than the fork ID slot for the seal. Yes, you can eye ball it, but you will never get the seal perfectly aligned like other seal tools do.
I just used this tool to install 36mm wiper seals. I agree that it is possible to set the seal too deep because of the design of the tool. I also agree that the fox equivalent will not allow this to happen. That said. If you lubricate the seal with a little oil first, it doesn’t take much force to set the seal. Gentle taps with a rubber mallet were sufficient to get the seal flush without driving it too deep. Honestly, if I had seen your review before I bought this tool, I probably would have just bought the Fox one, but having used it I think it is more than adequate and just requires a little more care.