If you were running 2.09 hf2, you very likely have the version 2 or 3 boot loader, which allows recovery without opening the case and connecting any pins. Don't connect pins - try easy first!
The Ubiquiti web-site has good directions. I won't repeat them here. You need to install and use a tftp server to recover though, not just putty. It's in the directions.
As for OpenWrt installation, this needs to be done with an initramfs image first, then you flash the permanent sysupgrade image. This post has a good summary for installation.
OpenWrt 23.05 runs rings around stock EdgeOS, which has essentially been abandoned by Ubiquiti anyway. I'd make the switch. Do install OpenWrt 23.05 though. 21.02 and 22.03 had some growing pains with the conversion to DSA.
EdgeOS has a version 3.0 on its way, but other than cosmetic changes and finally adding wireguard, it's same old same old.