How to increase the volume for all audio streams > 100 % in AOSP?

My Rationale

Occasionally, audio from a very useful proprietary application is too quiet to be audible. This is impossible to remediate at the application level because:

1. I am unable to request that the application author(s) implement a method of increasing the volume >100% intra-application, because it has no issue tracker.

2. I do not want to record the audio and manually increase the volume > 100 %, because that would be inconvenient.

My Question/Desire

Instead, hopefully it is achievable at the OS level. Consequently, [how] can I set any and/or all sound channels (especially the media channel) to > 100 % volume?

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The Feasibility Of The Desired

1. xdaforums.com/t/mod-volume-boost-on-all-default-sounds-by-150-200-full-dynamic-range.2708966 mentions that something referred to as "Viper4Android" provides this functionality, explicitly system-wide. However, I've been unable to ascertain confidently what it is, nor which of myriad projects sharing that name is relevant.

2. This is available in the "Audio" plasmoid of (V6.2 of) the KDE Plasma DE, so I don't consider what I request unreasonable.

   It's evidently not infeasibly difficult to implement for a custom AOSP distribution developer. Consequently, I expect it to be available in at least one of them, if it is infeasible otherwise.

The Placement Of The Question

1. Previously asked at android.stackexchange.com/q/259413, to interest, but no answer.

2. Asked at this Codidact forum, per the advice of proposals.codidact.com/comments/thread/9530#comment-26327. ^[1]

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