I've configured the stock cgminer in my S7 batch 6 with
"submit-stale" : true,
"queue" : "1",
"expiry" : "1",
"scan-time" : "1"
and looks like it's now submitting stale shares.
[2015-12-09 03:27:21] Pool 1 stale share detected, submitting as user requested
[2015-12-09 03:27:21] Accepted 00000058 Diff 0/8192 BTM 0 pool 1
[2015-12-09 03:27:22] opt_bitmain_freq:600 tmp:600
[2015-12-09 03:27:22] Pool 1 stale share detected, submitting as user requested
[2015-12-09 03:27:22] Accepted 00000058 Diff 0/8192 BTM 0 pool 1
[2015-12-09 03:27:23] Pool 1 stale share detected, submitting as user requested
Don't know if it's a bogus submission or if it's really happening but I'm on full speed p2pool
The cgminer default is always to submit stale shares. That entry in your config does nothing on current versions of cgminer. The problem with bitmain's driver is it deletes shares in the driver before even returning them to the main cgminer code in a way you can't configure in cgminer to avoid. These shares don't even show up as being deleted in any logs.