Have you tried removing dairy as well? We removed dairy and gluten and found it helped reduce tics. We also removed eggs as our child had sensitivities. And sugar is a big trigger.
Also, we went to an alternative doctor and had a stool test done (GI Map is a good one) as well as food intolerances blood (finger prick) done. It helped identify problem foods we should remove and the stoool test showed some gut issues we needed to address. Some people like the OATS urine test as well.
Testing along with working with an alternative doctor has helped us as we heal our chi