I took some photos of long tailed tits feeding on the suet ball feeders near to the children's playground the day before yesterday, and I couldn't help but notice that the suet balls were all in red plastic mesh nets even though they were inside wire mesh feeders.
The RSPB recommend that these mesh nets should always be removed as they can trap and injure or even kill birds that get tangled up in them.
Please could you possibly mention this to someone on site, as it looked like several feeders needed refilling as well, so once someone gets the ladder out they might remove these dangerous plastic nets from the suet balls too.
I will pass that on to the wardens. It is a common concern for the RSPB, as you say, birds can get their legs/feet trapped in them and injure themselves.
I do put out a ground feeder at the Centre here which is better suited and we do have bird table and feeding boxes up too. I will mention the net meshing though, so hopefully we have nice, safe and happy birds!
Thanks for your concern :)