This has been a pretty vicious decline without a rebound.
I do this trade with SLV over GLD because of the industrial uses of silver -- there is a demand for it OUTSIDE of the investment community, so theoretically (and in the long run), it has a base that GLD does not.
I agree with your marco analysis that the recent dollar strength has hammered commodities, pair that with the "CPI" report that shows no inflation, and metals go down. (I put that in quotes because the way the US government measures CPI is a crock of bs, but its still the number that gets put out.)
Expanding this trade to try to capitalize on the slide is perfectly reasonable. I personally am not going to, because I have almost 3 months to capture a bounce. If we break the SLV 17 barrier, then I'll double the position again. (If we then hit $16.50, I'll go lick my wounds).
In the last couple of years of doing this trade though, a bounce always has come along (and no that does NOT mean one is coming this time, but I am betting on one). I don't want to limit my gains if it happens tomorrow.
If you think that no bounce is coming this week, or if there is, it'll be small, there's any number of things you can do to increase returns:
1. Sell a vertical call spread for a gain OTM;
2. Sell OTM naked calls (more risk more return that 1);
3. change this trade to a calendar spread;
any number of other things jump to mind and would be appropriate if you don't see a bounce coming.