Unfortunately there's almost nothing you can really do as far as "mods" to a 6300.
You can replace the HDD and CDROM drives if they need it (
SD cards may work better).
It's a competent machine, but it's not particularly flexible. They're really great first Macs, reintroduction machines, something you give to a friend who has a kid they want edutainment for, or just a daily driver/beater type of machine.
Unfortunately there's not an awful lot for LC PDS that's both better than ethernet and runs on one of these. It's not nothing, but really, LCPDS Ethernet as you already have is likely your best bet.
Mirroring what has already been said, if you want Hot Performance or moddability, there's machines that will likely scratch that itch better.
The 6300/100 should perform Fine(TM) -it will be noticeably faster than the 630 at literally everything and if you max its RAM it should also competently boot into mac os 9.1 for things like fetching files, although you may find 9.1 is a bit heavy for daily use (it certainly is on my 6200, which I use with 7.6.1.)
EDIT/Add:
So my original computer was 630 CD. That had a "real" PDS slot? Just kind of curious what I could have upgraded that thing to when I was a kid. I begged my mom to buy Mac OS 8.6, only to find it wouldn't run on 68k... lol
There are upgrades specified as being "for" LC-PDS machines but they don't really use the PDS slot -- they plop directly into the 68040's CPU slot Some more/starter info:
https://lowendmac.com/2016/powerpc-601-cpu-upgrades-for-68040-macs-with-lc-pds/
Franklinstein mentioned this but these upgrades are sort of the long way around to just building the 5200/6200. Franklinstein didn't say this directly but as a caution on the 5200/6200 and 5300/6300 (plus the PowerBook 5300, 1400, 2300) - many sources still incorrectly cite some old Low End Mac articles that incorrectly describe the architecture of the machine.
They are slow, but not really as slow as described, and there's some software-based help available to make them feel more sprightly and outbench some of their first-gen PPC siblings.
That said, the second half of my 5200+ software recommendation is Speed Doubler 8 and using Mac OS 7.6.1 or probably 8.1. Those get you speed and reliability benefits over 7.5 on their own and then Speed Doubler replaces the 68k emulation components built into Mac OS with a significantly faster one. (Every system 7 on PPC mac can get that benefit but by the time you get to either 8.5 or 9.x the built-in 68k emulator outperforms the SD8 one.)