I'd like Ark to test and use the best compression method for an input

When compressed size is of sole or primary importance, evaluating the size of the archive resulting from using each compression method individually can be seriously tiresome.

Of course, some would say that the solution to this is to understand the advantages and disadvantages of each compression method (instead of manually brute-forcing the best solution, as described).

However, I don’t believe that this scales to anyone except the technically inclined:

doesn’t mean anything to most.

Consequently, I believe that a way for a user to:

  1. Instruct Ark to test all the compression types, leaving it running in the background;
  2. After which the user shall be notified

is the best solution. For most files, this shan’t take an unreasonable amount of time, and any time it might take is worth the increase in ease of use.