Well I did it...
I deleted the whole damned caboodle from the cardbox.
It was a chore, having too much in it and not necessarily words I wanted to revise, and as such I had stopped using it.
And I have started a new one.
You may have thought I had given up studying what with all the gardening. It is true that I am doing nowhere near as much at the moment, but I am still trying to do some every day. I am currently, and have been for a while now, concentrating on 8s. These are definitely my weak area...
I am attacking them from more than one direction.
I should have finished revising the top 10000 by the BMSC this coming weekend, and now I am just adding those I miss into the cardbox. I will keep working my way through over time.
Alongside that I am slowly going through the higher probability 8s. I started at 23k, as that was as far as I had got when I was card boxing. With these I do a quick test, breaking them up into chunks of 250 words. Those I miss or get but wouldn't bet my life on in a game get saved to a file in groups of 1000, e.g. 8missed-23k-24k. I then retest myself on those files several times. After several passes then those missed also get added to the cardbox.
It is actually quite fun doing this - learning some new words as opposed to constant revision. I am currently going through 28001-29000.