If you are still looking for a solution, I had a similar issue with bypassing inserts and sends.
To cut a long story short I was able to build a Cubase macro as a workaround until Steinberg hopefully add the feature/short keys. The macro example I show is set to bypass Inserts but you should be able to modify it by changing the Insert command to a bypass Chanel strip command which is also available in the Key editor. Try it out and let me know if it worked for you.