If anything take a piece of an old tube and wrap the housing with it, maybe it could add some grip and prevent movement/slapping. what exactly did you use?
Rode again and there was no slap, big front loop on the cable pulls any slack out from underneath the top tube luckily. Can run the guide with no other cable straps or zip ties.
I know right? Even without the engraving its still pretty cool. I haven't gotten around to testing it yet to see if the cable slaps in the middle but I'm hoping I can run it without a cable strap for a clean look.