Remove exercises from Today's Activity

Would it be possible to get a little cross that allows you to remove an exercise from Today's Activity on your dashboard?

I've added one by mistake a couple of times (once by forgetting to refresh and adding a custom exercise to an old day, and another by accidentally unticking a previously completed day on a challenge then ticking it again) so being able to get rid of them would come in handy.
 
You can remove them here but I agree a little x in the overview could be more practical :)
Thank you for the response! More looking for removing custom exercises and/or a day from a challenge without removing the entire challenge history, but good to know in case I ever do need to get rid of a workout!