Avoid rebuffering when modifying TrackSelector parameters

[REQUIRED] Use case description
This is the exact same request raised time ago in the Exoplayer project (issue #6630).
I have an app using adaptive media, where in certain circumstances I want to reduce the bandwidth consumed by the video/audio.
I do so by setting new filtering criteria in the track selector, as follows:

    DefaultTrackSelector.Parameters currentParameters = ((DefaultTrackSelector) trackSelector).getParameters();
    DefaultTrackSelector.Parameters newParameters = currentParameters
            .buildUpon()
            .setForceLowestBitrate(true)
            .build();
    ((DefaultTrackSelector) trackSelector).setParameters(newParameters);

However this forces a reset in the playback (removal of chunks already available), with rebuff for a while.
The same happens when I remove that limitaton.
Of course rebuffering is more evident if I force the selection of a high bitrate track.
I need instead an uninterrupted playback

Proposed solution
I need something like:

trackSelector.SetParameters(newParameters, booleanWetherResetOrNot);

such that (in case of "don't reset") the playback is not interrupted, and chunks already downloaded or being downloaded are not removed; simply, the new trackSelector parameters would take effect at the next choice of the chunk to be downloaded.

Alternatives considered
In Exoplayer #6630 Tonihei finally showed an application-level solution (at that time I already implemented a more invasive blacklist based solution and didn't revert to Tonihei's suggestion). I'd like to use that solution now, so I tried implementing it. I can inject my custom class, and I can see it being created and invoked. However, I have no mechanism to access the actual instances of that CustomTrackSelection in order to dynamically set the parameters I need. Would someone be able to complete Tonihei's solution by showing also how to actually set a parameter on that class, dynamically?

Thanks in advance