Finally solved by following the "Neederland" friend post.
After hanging up at 50%, the updater detected the 2.8 Helix LT but after trying to continue with the update it'd promt the "Error" message.
So,
With HX Edit 2.8 installed, I uninstalled helix update 1.17 and reinstalled it again.
Closed them, switched Helix LT on with buttons 6 & 12 pressed. (Forced update mode ¿?)
Launched Helix updater 1.17 with Helix LT on.
Then updater DID detect my LT (2.8).
Selected it and...
Device updated.
Phew.
Thank you all for the little bits of support here and there!
