Interrupter (cross) brake lever cable guide wedges? Interrupter brakes require the brake cable to angle away from the bar to meet the lever at the proper point as shown in the picture below. You can see the handlebar tape doesn't carry on closer to the center because if it did, and was wrapped tight, it would put a harsh bend in the cable. But it seems the right tiny bit of molded plastic to guide the cable off the bar right into the interrupters at the correct angle (shown in red on the left) would allow you to wrap the tape nice and tight right up to where the interrupter levers clamp on the bar.

Is there such a cable guide wedge thing? If not, has anyone made their own? It would be nice to bring the handlebar tape nicely finished right up against the interrupter clamp.
When I wrenched for a cross team we just taped over the housing. We also would position the levers further out (unless you're running narrow bars.) Keep in mind there's no need to pull the tape so tight that it would bend the cable housing. You want to pull the tape just snug enough so it doesn't slip. If you get to the end of the bar and let go of the tape it shouldn't unravel. If it does you likely pulled it too tight. Also no need to use so much electrical tape at the end. If you want a really clean look cut end of the tape at a 45 degree angle so it lies flat when you finish wrapping and hold it in place with a dot of superglue.