So if I needed some planned downtime and I didn't want to mess up my shares, how would I best choose when to shut down the miner?
Right at the start of a round, i.e. when a block has just been found.
Hold the fuck up a minute! If my miners go down for 5 minutes I lose 50% of the work they have done for that block?
I got these things on Wifi Every time a big truck drives by they go out for 20 to 30 sec. What measurement of time triggers the "oh shit he's a pool hopper fuck him over" device?
On a longer round, yes - the score is based on an exponential function with the round time as the exponent. It's scaled by a factor "1/C", but on longer rounds this will dominate - check your score under my account. More info found in the link given above (
https://bitcointalk.org/index.php?topic=1976.msg50002#msg50002 for your convenience). The longer the round, the more important staying connected (and submitting a share close to the point a block is found) becomes.