As long as it works for ones needs it a job well done...without a loader I'm surprised you have not fabricated some sort of carry all...with a trimmer caddy incorporated...?
Sure they make a few different attachments like carry all designs but there not cheap for no more than they are. Only thing I’d change is the top support, get it off the tractor so if you raised the hitch accidentally or what ever it wouldn’t damage the trimmer.