The setup is quite good and the whole thing rather creepy. The enemies might be too much for characters of lower levels in the tier even with the APL adjustments. A nice touch is a number of options for the DM to set up encounters to be a better matchup for the players. Considering the death curse, the possibility of permanent reduction to max HP may also be too much for lower-level characters. Unlike the others in the trilogy, this is where the target APL is really probably a minimum for a good session. The other option, since the trilogy isn't really tied into the death curse, is to run it after your players have dealt with the death curse in the hardcover if they're still in the appropriate tier and interested in running other adventures in Chult.
[4 of 5 Stars!]