HSX has said in the past that they will probably NOT do this. Those of us with huge ports would love that, as it would be a place to put additional cash, but HSX is concerned how raising the limit would 'skew' the data that they need to sell to studios. I also think that they are concerned about more manipulation of stock prices if people can buy more shares of stocks.
It's not unusual for traders to have more than one port (and also allowed by HSX "IF" people don't use them to manipulate prices, and trade differently in each port) so by allowing us to buy say, 100K shares of a stock, this may affect its price, and HSX (as you know) uses pricing data to sell this info to studios, etc., to give them tracking information regarding a movie's popularity, etc.
While I would love to be able to buy 100K shares of any stock, I don't think it will happen in the forseeable future - but you never know.
In the "olden days" of HSX, we could only buy 10,000 shares max of any one stock, and over time they changed it to 50K shares, so it COULD happen in the future, but for now, I don't think so.