I recently installed OpenWRT (trunk build from the 30th of October) on my Netgear WNDR3400v1 and it's running quite well. After reading more of the Documentation, I just discovered that LEDE exists and would like to upgrade to the latest release version of LEDE to try out some of its additional packages.
According to the Quick Start guide, I should be able to upgrade to LEDE directly from OpenWRT using the sysupgrade option. The guides specifically state that a file ending with "-sysupgrade.bin" should be used for this process, but when I search for my device in the Table of Hardware, the upgrade URL points to the same "-netgear-wndr3400-v1-squashfs.chk" file that is used for installation from the factory firmware.
I can't find any special instructions for updating this router in a different way. According to the OpenWRT wiki, this file ending in .trx should be used to update OpenWRT, but no such file exists on the server. Does this mean I can use the same .chk file to upgrade my router, or should I be using one of the .trx files from the mips74k branch? Also, will upgrading from a more recent (30th of October) trunk build of OpenWRT to a slightly older (18th of October) release version of LEDE give me any issues?