8M ROM/32M RAM - worst case scenario?

My TP-Link TL-WR842ND v2 has been happily running OpenWRT CC for quite a while. Basic system, no additional packages. I was thinking about moving to LEDE but was stopped by the warning to not install on devices with so little flash and RAM.

Question is, if I ignore that warning and do try to upgrade to LEDE, what's the worst thing that could happen? Would it just refuse to complete the upgrade and leave OpenWRT as it is? Might it brick the router? Something in-between?

I do not think it will brick your router because of the space at least.
I have installed LEDE on my TP link 740n which has 4 MB flash and 32 MB RAM.

The worst might be constant crashes and reboots due to RAM exhaustion.

Kernel and apps take slightly more RAM than CC15.05, so 32 MB does not leave much extra for even a short-timed high peak memory usage.

Installing LuCI, DDNS, adblock etc. will likely crash the router after a while.

You might be ok with a basic router system without any fancy apps.

(8 MB flash is ok, but the 32 MB RAM is the crucial point.)

Ah, I will want LUCI ... came included with Chaos Calmer, but I guess needs to be separately installed in LEDE?

Would I be well advised to muck around with zram or swap on usb, or just try to keep things as minimal as possible?