I've been trying to update some Aeotec devices using the HomeSeer .hec files from their ZFlash utility (which I bought ages ago - the .hec files can be DL's from Aeotec too), but Device Firmware Updater just sits there at the 0% mark and never goes any further - after reviewing the logs I found the following error everytime:
Homeseer's format is encrypted, probably because they want you to buy and use their special flashing software in order to do this (and probably because some of their products are branded otherwise-generic whitelabel products and they don't want you putting their firmware on those). I think the most consumer-friendly outcome would be for vendors to use the open formats instead, then any software can do it.
That being said, I recently got Homeseer's Z-Flash software plus their Z-Wave stick for $25, which isn't a bad price IMHO since a stick alone can cost that much (and contrary to the product picture, I actually got their new "G3" 700-series stick and not the G2). Normally the bundle is about twice that price and the software alone can be found for a little less, but both are on sale now and also were last weekend. I hate to encourage them to keep doing this by buying it, but for their software plus the stick I decided to go for the $25 option anyway.
My research suggests it's Aeotec who don't want to provide unencrypted FW files. As Aeotec are the ones doing the encryption and posting the FW files to their support site, perhaps they would be willing to provide the decryption keys to Hubitat too, instead of creating another file format? Especially if it's just a standard HEX file with encryption on top.
That is a really good deal. I bought an Aeotec Z-stick gen 5 (now upgrade to g5+ FW) several years ago and the z-flash software when I was considering moving from Vera to HS. It's been a handy utility to have.
However, joining Z-flash to Hubitat and flashing OTA seems to be very hit and miss - I've even bricked a device this way. It's fine doing direct device upgrades tho.