I personally think that SFX are part of the artwork, so unless they're really clearly added in via typing instead of being drawn, I think SFX notes are more respectful towards the artist.
Even if you are redrawing most SFX, I'm still of the mind that you should always follow the Jojo Rule: if the SFX already look cool, whatever you do to replace them will probably not look as cool. You're just spending a lot of time and effort to make something that will, at best, be the same quality as leaving it and adding SFX notes.