I don't use openwrt, but I do use linux because, like
@devast, I want CAKE SQM. To get somewhat equivalent functionality to CAKE in opnsense, you'd have to do htb+fq_codel since FreeBSD does not have a CAKE implementation. I don't think you can configure that from the GUI. The GUI config for shaping in opnsense is, IMO, pretty limited. CAKE works great for fairness and shaping and also works with hardware offload. The disadvantage is it uses quite a bit more CPU than fq_codel (but less than htb+fq_codel).
www.bufferbloat.net