mod_lua is still marked experimental because we did not yet expect it to be complete or the APIs to be stable. So we did expect and wanted to allow incompatible changes.
Now that a few of us are working on it I expect it would be useful if backports could be done quicker for some time until we think we have approached stability. So I plan to start a vote an switching mod_lua in 2.4 to CTR. Please let me know your objections if there are any. Regards, Rainer