I'm getting some distinct Spleenomized Vibes here...
Anyway, I've hit your emitter with a big brick a few times and it appears to scale normally like all those ludicrously huge VFX things I did... and keep meaning to update again.
1. Obtain a big brick.
2. Open your emitter in Notepad by hitting it with the brick... or clicking on it with the mouse if you really must.
3. Ignore the dummies, go straight to the actual emitter node(s).
4. Scan through all those nebulous and confusing lines and seek out the two called "sizeStart" and "sizeEnd".
5. Holding the brick firmly in whatever hand is unSpleenomized, hit those lines repeatedly until the numbers change.
6. You can just type new numbers with a keyboard if you're really set on not using bricks.
Those two lines are the heart and soul of changing the dimensions of emitters. Obviously I cannot tell you what numbers to put there because I don't know what size you want the thing to be. You should freely conduct unethical medical experiments upon the emitters until satisfied.
The higher the number, the larger the emitter should be.
You shouldn't need to alter any other entries in the model.
The end.
Hopefully.