(no extra stuff, just a plain, low traffic Ethernet router)
If this is the case, then the absolute BEST solution is to enable the ram drive and then enable "Run from ram" option. At that point the hard drive will never spin other than to boot. I have used this option for a number of routers and print servers and it works very well. It also makes them sort of bullet proof for power outages along with just power cycling them.
With regards to changing scripts, it does not require Zipslack. All you need is the FREESCO OS and you can easily modify the ramdisk without recompiling anything. But the scripting is extremely cryptic and finding all of the components of a single command can be challenging at best for anyone who did not design it and modified them repeatedly over the span of about 14 years.
If you are afraid that you might make a mistake. The chances are high that you will never learn anything.