Sorry for the double post, I just beat the game, very well done! I can't wait to try this again on the polished engine when the time comes.
A few things to suggest for that time, if at all possible;
1: Samurott line needs Sacred Sword in its movepool like it has had since gen 6. Its a egg move there made possible by smeargle copying either the swords of justice or a honedge. In this it might be better to make it a red shard or yellow shard tutor move, it can then become a move a few other pokemon can learn to justify Samurott getting this movepool. Also I would reccomend giving it Razor Shell, as that is traditionally its signature move.
2: Might be a good idea to change the types of some HM moves, allowing them some additional viability. Cut is often made a grass or steel move for example. Perhaps giving it a critical hit chance might also be useful. Likewise Strength might be better as a rock type attack or fighting type attack with a chance to raise the user's attack.
3: Fix the way the DVs/IVs work on specific genders. In vanilla crystal, I cant remember if this was a bug or not but female pokemon were more often than not weaker than their male counterparts, and I saw that on occasion this issue still exists in the hack, as my Gigalith's attack was a 1 out of 15. This was because gender values affected the attack stat, somehow. Also shiny pokemon never had DVs/IVs for their special attack and special defense above 10, despite how in the 2nd gen games shinies were supposed stronger than their standard forms.
4: More moves (if possible). I mentioned Razor Shell above but there were a few other pokemon who lacked necessary moves (IMO). Gigalith without Heavy Slam or Iron Head feels wrong, even if it isnt a steel type pokemon for example. This is critical when we factor the polished engine adds special/hidden abilities as a lot of pokemon will be grossly underpowered without a certain move to work with a specific ability.
5: More TM variety. This technically could fit under suggestion 4 but having more TMs can help in the long run. The mall on route 9 should have more than just the moves for Fire Blast/Thunder/Blizzard/Hyper Beam, something I always found lacking in both B/W 1 and 2. BEcause it is a late game store, you can get away with adding more very useful TMs there.
6: Last suggestion; Its a shame the world tournament has no further use after you beat it, this should maintain it's purpose as a Battle Frontier location. What would be cool though is that we see different game modes for the world tournament, something like the way the cups in pokemon stadium 1 and 2 worked. The concept of the Little Cup in competitive play originated in gen 5 as it is, and getting not just battle points for winning but also trophies to use to decorate your bedroom like you could in vanilla crystal would be cool. Would also be cool to get special rare pokemon this way like how in Staium 1 and 2 you got things like a Psyduck with Amnesia (which made it overpowered in gen 1) or a Farfetch'd with Baton Pass in stadium 2. Getting rare pokemon with moves they can't learn any other way would be a nice bonus for world tournament participation.