Um... there's something you should know.
It's actually highly classified, so don't go around telling everyone. OK?
Even when you re-point the table, you can only have like 12 different OW palettes used in a map at once. (I'm not sure if the number is 12, it's just for examples sake)
When a map is loaded, it goes through all of the OWs on it and adds their pallets to the OW palette table, in RAM.
As a result, there can only be 16 different, palettes for OWs, and some of them are used for things like the menu, and the text-box. Thus there are less than 16 available.
For example you could have palette 0x55, (random number, but possible if you make the table large enough) and want to use it with an OW.
The problem is that in order to actually use it, you have to overwrite another palette already in RAM (for example 0x03), thus effectively erasing that entire palette, and messing up any OW's that might have used it.
The gist of this all is: when you expand the OW palette table you really aren't adding new palettes in RAM, just overwriting old ones.
Now, I'm not saying it's a waste of time to expand the OW palette table, depending on what you need to do, it may be worth it,
but it's a juggling act, because in reality, you can only use one or two of your new palettes at a time, before you start getting nasty artifacts of the 16 palette limit.
If you're still interested, I'll talk you through expanding the palette table.