I now have 35 issue statuses in one of my Redmines. Before you criticise this is because I had two and was adding a third completely separate workflows for different trackers:

Trackers Bug, Feature, Support, Design all use a fairly standard development pipeline with 13 steps from design through final acceptance on live server.
Tracker Recruit also has 13 steps from Invite to Interview to Acceptance or Rejection.

My new tracker for Failure Analysis adds 10 new statuses to the list. However when I try to edit the Workflow with "Only display statuses that are used in this tracker" unchecked (so that I can add in my new statuses) I get the following exception:

Request Entity Too Large

The requested resource
/workflows/edit
does not allow request data with POST requests, or the amount of data provided in the request exceeds the capacity limit.
Apache/2.2.31 (Amazon) Server at redmine.jawasoft.com Port 443

I guess the grid of 35 x 35  = 1225 posted values is too many for HTTP? I did some research and PHP typically limits to 1000, other servers to other values.

Is there a quick fix - a server setting I can change?¶

I dont feel I am using Redmine unreasonably here - but the whole Workflow UX becomes almost unmanageable when you have more than 10 or 15 statuses.¶