[RegistryValueWrite] question/issue

I am trying to portablize PotPlayer (a freeware audio & video player similar to AIMP: https://daumpotplayer.com/ ) and am having some success with it except for one issue. It writes a registry entry into HKCU\Software\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION where there is already an existing key/value.

I have tried using a [RegistryKeys] entry, but it removes/replaces the existing entry for as long as I am running the app, so the pre-existing value is unavailable until I exit, potentially breaking the other application.

I have tried using a [RegistryValueWrite] entry, and while it will successfully add the correct entry into the correct location without disturbing the existing entry, it doesn't get removed when I close the program. I don't know if this is by design, or if it's user error on my part.

I have searched the forums and found Pot Player in development (https://portableapps.com/node/27285) but the person developing it has yet to address/include any registry movement. i.e. the current version in development leaves registry entries in:
>>HKCU\Software\Daum
>>HKCU\Software\Microsoft\Internet Explorer\LowRegistry\Audio\PolicyConfig\PropertyStore
>>HKCU\Software\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION
>>HKCU\Software\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_ENABLE_CLIPCHILDREN_OPTIMIZATION
I'd like to avoid that if possible.

I am running:
-Win10 Pro x64 (the issue occurs in both 32 and 64 bit versions of Pot Player as it writes to the same key in both versions)
-PortableApps.com Application Template v3.4.1
-PortableApps.com Launcher v2.2.1

The entry I am attempting to get to work:
[RegistryValueWrite]
HKCU\Software\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION\PotPlayerMini=REG_DWORD:2AF8

Existing Key Value I would like to keep while running the app:
HKCU\Software\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION\OneDrive.exe=REG_DWORD:2AF8

TL/DR: Is there a way, using the Launcher, to add (on launch) and remove (on close) a key value into an existing registry key without disturbing any of the existing values?

Thanks in advance, and sorry for the long post. I just wanted to tell people what I've already done so we don't cover ground that's already been covered.