Dave - So, you can lift the chain UP on the chainring, not OFF it as in dropping the chain from the sprocket. You can always do this to some extent, and it tells you very little in regards to whether the chain “tension” is correct. The only good way I know to do this is the measure chain slack midway between the chainring and cog when the chain is tightest.

As to the Park tool, it is just a go/no go type tool, and .5% is not very much chain stretch. Also, the results can be skewed if the chain rollers are not very precisely made. Anyways, the direct measurement method that Tim suggests is much more reliable.

Let me recommend that you replace that worn Origin 8 chainring and replace it with something better.