Do you have any suggestions for wells that reach drawdown stabilization between 10 and 50 mL per minute?

On a practical basis, when your flow rate gets down as low as 10-50 mL per minute it's going to take a long time to purge that well to get stabilization to occur, as well as to fill your sample bottles. It’s not necessarily a hard and fast rule, but that’s a well where I would use a breakpoint of about 100 mL per minute for a stabilization rate. If you can’t get the water level to stabilize readily at around a 100 mL per minute then you have to decide whether or not local purging and sampling really is the best choice there. You can use a passive or no-purge methodology unless the sample volume required is several liters of water or more because of the parameters being monitored. There really are no passive or no-purge devices that can get more than about a 1/2 liter or a liter of water maximum, and some of them are limited to as little as 80 to 100 mL of sample volume. Those extremely low flow rates may necessitate the use of a minimum purge approach, where you just pump the volume of the pump and tubing and collect your samples. You should have adequate sample volume in the well, and then you eliminate the whole concern about indicated parameter stabilization.