I’ve used the @ TDC firing method, with a small cam I think it’s fine. Anything bigger or to be sure the EO/IC or the chart that has you doing about the same in 90° intervals is superior.

I’m kinda of a newb so I use the chart. I’ve done EO/IC at least once but depending on where the engine stops the lash I measured varied by a thou or two definitely WAY faster tho