Short answer is no - there is no way (for you) to get out of your equity positions at random hours based on futures. Long answer - of course there are ways to hedge, but depends on what access you have. There are mining and producing companies, Jr. mining and Jr. producers - explorers (all global of course). Additionally you have some options to get out of your position at any hour if needed. A broker will ALWAYS take you out of a trade (or hedge you) at any price, any time.
why not switch to XAG/USD completely? some derivatives may not available i guess. in the last two months I saw several great moves in Silver futures overnight, while the daily SLV sessions were muted. It is frustrating to miss this kind of action. SI is too expensive for me. could anybody confirm that IB offers XAG/USD?
=========== Surf Trend; SLV options look plenty liquid, narrow bid ask .......... The timing of your question suggests you are skilled enough to simply exit regular market hours. Silver ,SLV still looks short term bearish; long term uptrend