cbepctl max_num_writers cannot increase writers

With a command such as
/opt/couchbase/bin/cbepctl localhost:11210 -b bucket set flush_param max_num_writers 5

cbepctl seems to only be able to lower the number of writer threads on the fly not increase them above the maximum set at bucket startup. Can this be fixed ? If not can an additional cli command that changes the startup max_num_writers be created and documented that a bucket restart is needed for this new command?