ethercon lock is oriented to side where the casing is, so unpluging of cable is an issue. I would suggest to get rid of casing offset around ethercon, also xlr connectors are cheap and may be a source of problems when using very often. if it is for instalation there should be no problem.
using as an 4 way multicore looking to be good, and as we all have bunch of ehternet cables laying around it is a great possibility to use them.