I would cut it out.... but i can see where others may be hesitant.
Most suspension manufacturers offer replacement bracketry for suspension items that require cutting to install their lifts. So if you buy their lift, you know that if yyou ever want to return it back to stock you can just buy the replacement bracket. Might be something to offer with option 3... let them know you will sell/provide a bracket in the event they ever want to remove the bumper and go back to stock.
Edit: just realized that i didn't fully understand your post... looks like you already said exactly what i said about having a "replacement crossmember"
