Is it possible to add support to veracrypt for any of gl.inet routers (for the usb drive)"? I think it would be a great thing to have when you travel. Thanks
however luks is supported in openwrt and there is software for windows if thats your OS platform.
If you just want to encrypt disk. You can refer to this link: https://openwrt.org/docs/guide-user/storage/disk.encryption.