1. Print slow with .4mm nozzle and 0.1mm to .2mm layer Hight to avoid having water intrusion issues. PLA works great. The people that say that PLA leaks between the layer lines are printing with incorrect settings. You will have 125+ hours to print this correctly. It's a beautiful model, don't ruin it with a bunch of Flex Seal on the hull bottom.
2. There need to be alignment tabs and more surface for glue between the different hull sections but there aren't so when gluing together this will be where you potentially get leaks. Many Youtubers building this boat have remixed the design to include alignment tabs, but none have been kind enough to share files with those of us without the skill of 3d modeling.
3. On the transom of the boat (the back), you need to install bolts in the holes for the outer stabilizer tabs BEFORE assembling the hull sections. I put mine in and then dropped a big glob of epoxy on the bolt heads to hold them in place.
4. The motor mount doesn't work. The motor will hit the half round radius on the hull bottom. There is no way to easily design a new one because the motor will then be too high to accept the prop shaft. The outdrive needs more downward adjustment to allow this. That would also correct the issues of prop cavitation that many report. The only way to install the motor is to melt or cut away the radius on the hull bottom for motor clearance.
5. The passage in the rudder for water cooling is too small to flow water well. I found that I needed a separate electric water pump for cooling.

Update: I found that if you use a shorter prop shaft, 150-200mm the motor sits further back in the hull and can be mounted with Sergi's mount