Specify this might require whole GHC JS Backend rebuild to make effect. This option does not work well when applied “on the fly”
Also keep in mind that this option is more like a hack for current GHC JS Backend. Better find a way how to avoid its usage.
Also, if you have a good progress it would be nice to create an article which will describe your experience like we did. 
We have to collect experience with modern GHC JS Backend to see whole picture of such complex transition.
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