There are two parts of this issue that need to be discussed separately.
1. The information that PS
sends to players about their foe Pokémon HP.
2. The information that PS
displays to players about their foe Pokémon HP.
The information sent can, in principle, be the amount of 48ths, 100ths, or both. Note that sending both pieces of information would directly allow the calculation of EV spreads from the damage, as described by
david stone's excellent post:
http://www.smogon.com/forums/threads/on-cartridge-accurate-hp-reporting.3479677/page-4#post-4609225. (It also explains the difference between the information sent and its display.)
When the information sent is a percentage, there is no doubt that the display should also be the same.
However, when the information provided is fraction of 48, a corresponding range of percentages, an approximate percentage, or the exact fraction, as well as their combinations are all options for the display.
An user-friendliness order can be defined as
Exact fraction ~ Range of percentages < Approximate percentage
However, it's also true that the game does stuff in 48ths, so the fact that values are given as fractions of 48ths is moot, and we are only left comparing the numerator with the corresponding damage for Hazards / Residuals, EXCEPT that the damage calculator outputs results in percentages, but... you know... we CAN bring 48ths support to the Damage Calculator!
Now, there are also people who fear that, if we switched to restricting HP information to 48ths, some members of the community might depart to other simulators in the search of more accuracy and more comfort for them, but there exists a preliminary approval of the implementation of an option to make it so that if BOTH players agree to it in-battle, they will get their shiny "accurate" percentages back. This is no different from an impartial judge sharing this information between both players.
So, fear not that people will leave due to information loss, or that the Calculator will be incompatible with PS. These things will be sorted out in due time now that we know the concerns of you all.