It would have literally exactly the same effect on your ratio; why would the site's staff want to code such a useless option?
Sorry, but that's actually wrong.
1Gb upload, 10Gb download, ratio = 0.1
Let's pretend you remove 1Gb.
1Gb upload, 9Gb download, ratio = 0.11
Let's now assume you further remove 5Gb.
1Gb upload, 4Gb download, ratio 0.25
Now let's look at the system we currently have in place.
1Gb upload, 10Gb download, ratio 0.1
Add 1Gb upload
2Gb upload, 10Gb download, ratio 0.2
And now, a further 5Gb
7Gb upload, 10Gb download, ratio 0.7
So which do you think is the better option?
And these are just small numbers. The bigger the number, the more enormous the discrepancy.
For example:100Gb upload, 1000Gb download, ratio 0.1
Upload 100Gb, download 995Gb, ratio = 0.10050251256
Instead, add 5Gb to upload
Upload 105Gb, download 1000Gb, ratio = 0.105