Big bettor at the table
I would spread conservatively at your home haunts, or any place you think you'll become a familiar face in over the long term.
Bet size is just as important as spread, IMO. I get the feeling that the largest bets in a particular pit are more likely to draw scrutiny than the largest spreads. Sure, $5-$100 will get their attention, but $25-$250 would be scrutinized first - obviously, these examples should be scaled up/down according to how far out in podunk you're playing.
If you're Wonging, a spread of 6:1 is sufficient to be profitable without bad variance.
There's a tiny place I have played twice - it's several hundred miles away, but near one of my vacation spots, so I try not to burn it out - which clearly does not see many bettors above $150. I play two hands there, spreading 6:1, and am nearly invisible because my top bet is in the same red color as my bottom bet. If I were spreading 10:1, I would certainly be on the radar, as I have seen ploppies there get careful inspection for bets past a certain threshold.