If mobility is a big concern, I’ve found that some shin guards with a bulkier fit tend to get in the way during quick turns. A snugger fit with good strapping is key. If you're open to different styles, https://fightsupplies.co.uk/muay-thai-shin-guards/ has some options that might work if you’re after something lightweight with solid protection. Some of those designs offer great coverage while keeping movement unrestricted.