Reversible data won't matter in this case. If it was necessary we can add them to the views and it's not a big deal. Indexes are not necessary on the reversible data though as the data is too small to be worth creating an index for it.
The created indexes are necessary for this app but I don't think they are necessary for the haf itself since they won't be necessary outside this use case.
IMHO haf should stay as generalized as possible and don't put the burden of every single app on the HAF node operators unless they choose to run that app.