As I've been developing a fully-fledged PLUT reactor prototype, I've realized DSTW does not slow neutrons, which foils the entire design. Many modern reactors use water for both cooling and as neutron moderators, slowing the neutrons and increasing the likelihood that they'll react with fissile fuel. To do this in TPT I would have to use regular water, but that conducts electricity and ruins the reactor which uses sensitive electronics.
This is only a specific use case, but I really don't see a reason why regular WATR is the only form of water to moderate neutrons in TPT, it seems like a rather useless case of exclusivity.