There is a bug in GarminExpress which occasionally appears where it will offer a "one-off" map update to a device under Garmin's latest maps guarantee, even though the device may be many years old but has been recently returned to factory settings. That guarantee is really solely to ensure that devices which have been factory programmed with mapping are given the very latest mapping immediately after purchase. If you let the device as 34xx get a satellite fix that option may no longer be offered. Rather than fake it on a USB stick or media card during the update, i would now re-connect it to GE directly with a minimun size 16GB microSD in FAT32 ready to install when prompted by GE because obviously all of EU and ancillary files cannot fit on your 8GB internal memory. It's not your fault Garmin has messed up so you don't need to hide it. Any unlock and GMA files will be legitimate so don't worry.

GE is reading the device's HWID to determine the type of files to supply in the update, however it's servers have the UnitID recorded to determine it's original factory mapping entitlement (i.e. the map region or sub-region and LM if appropriate). It should supply you with all the appropriate JCV, ASR, etc., etc. files along with the one-off All of EU map update. So if the offered update is still available it should all work correctly without you having to find other files to download separately. Be sure you accept all offered updates for desired Language files and Spanish voices and any other associated files you're offered too. Then voice command should work, as will Junctionview.

Those posts in the other thread are confirming that 37xx uses ASR1 and 34xx uses ASR2 files, and that the language-specific SRD file for Spanish must be loaded for you to use Spanish for Voice Command too. As i said, GE should give you everything you need to work with the 2025.10 mapping.
PS: No need to 'code' internal links to threads/post in here, only most outside links other than download sites.