Adding kld + loader tunables: sanity check before going ahead

[Stilez]

I've got my monitor working how I want it, with FreeNAS, and it looks like the same settings should work well on OPNSense as the OS is clearly compatible.

Since errors in loader config can be a real problem, I want to sanity check before going ahead, even though reading the forums it looks OK.
I want to load the vt driver and a couple of others, and then set some loader tunables related to them.

• Do I just add them to "tunables", and OPNSense middleware will figure which to apply as loader / rc / sysctl?
• Does the order matter?
• How would I recover if I find I've made a mistake and it won't boot properly, or is the system resilient against user errors in loader/rc tunable entry?

Thanks for any quick answers on this, so I can go ahead. If it works, I'll add it as a request or forum post, so others can benefit too.