I hesitate to offer any opinion about how to engrave or tool use, however; I have offered this in the past. As my babble is often unfathomable I thought I would reiterate, hopefully the contents will not be found offensive or objectionably tedious.
I have found a round works very well for background removal, however; Mike Dubber's Speitzer used with a round heel exceeds the rounds capabilities. I use a universal template with the heel template rounded to offer a 'round' graver in the vertical position and tilted in either direction it will remove metal to nearly flat without any possibility of the heel digging in.
Works very well for me but as we all know I'm a bit abnormal to say the least.
Bob