I've received a brand spanking new HD 10 Plus today. Oddly though FTB recognizes it as "Amazon Fire HD8 (2018)" though

Is this posing any issues when going through the process of "fixing" this tablet (going with the standard recommended settings)?
Also, when trying to install the Nova launcher as well as Google Keyboard I've gotten the same error (sideloading was already enabled):
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Toolbox APK Installer
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An error occured during installation:
Performing Streamed Install
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OK
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Any solutions or ist this a big in the current version v26.1?
EDIT:
And I've just gotten another error message (4 times!) when trying to install google services
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Fire Toolbox V26.1
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INSTALLATION FAILURE:
adb: failed to install C:\Users\Jodan\AppData\Local\Datastream\Fire Toolbox V26.1\bin\Google Services\PlayServices9.0.apk:
Exception occurred while executing:
java.lang.IllegalArgumentException: Bad user number: -S
at android.os.UserHandle.parseUserArg(UserHandle.java:351)
at com.android.server.pm.PackageManagerShellCommand.makeInstallParams(PackageManagerShellCommand.java:2214)
at com.android.server.pm.PackageManagerShellCommand.runInstall(PackageManagerShellCommand.java:903)
at com.android.server.pm.PackageManagerShellCommand.onCommand(PackageManagerShellCommand.java:158)
at android.os.ShellCommand.exec(ShellCommand.ja
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OK
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Any solutions to that?
EDIT 2:
While the Device ID in the bottom left has changed it still is not correct as this is a "plus" and FTB shows it as "Amazon Fire HD 10 (2021)".
The Fire OS Version - according to FTB Device Information - is 7.3.1.9. And I don't know if this is normal since this is my first Fire tablet but shockingly the Security Patch version appears to be 2018-10-05. Over 3 years old for a 2021 model tablet? Surely this can't be right, can it?
EDIT 3:
After manually changing the USB connection on the tablet from "No Data Transfer" to "Data Transfer" (that's both direct translations from what it says for me on the tablet in German - I've tried to change the tablet's language to English to see what it says but whenever tapping on "Keyboard and Language" - "Languages" I'm just getting pushed back to the Device Options menu...) I now was able to install google services without an error message. Same for the custom launcher.
EDIT 4:
Manually selecting apps to disable in the Manage Amazon Apps section... there is no "Run" or "Execute" button. So I'm not entirely sure if simply selecting apps is enough already to disable them.