I'm sure it would leave a line IF you just use it in the normal way after cutting out the sentiment.
But I would find directions for using small embossing folders without getting the lines from them. That would be the situation you would be in...so the instructions would be the same.
There's also instructions for how to do partial embossing with a folder. You could just exclude the area that you don't want.
Check out my Bigshot Embossing Board on Pinterest for several sites with instructions:
CRAFTY TIPS...BigShot Embossing