All our routers are "open source" and not locked in any way. When you buy a router from us, you own it. You can install a different OS, upgrade the hardware, install extension cards, and do whatever you like.
With the exception of ARM devices, our routers allow installation of any operating system, including OPNSense, pfSense®, OpenWRT and others.
Hardware assembly and basic OS installation are always free of charge.
If you are not sure what you need, check out this article in our knowledge base: Which router should I buy?