Good question. Which value you prefer for the Pool Refresh Rate depends on your mining strategy.  A shorter refresh rate is good if you prefer small shares in coins with the highest estimated earnings. That will help spread your mining work around and help reduce the risk of investing too much time in a coin whose value drops after you mine it, but before the pool pays your share for it. A longer refresh rate can help you earn bigger shares in a smaller number of coins.  That can pay off for high-value coins that are not mined quickly, like Raven. However, the downside is that you are more at risk for losing productivity to orphan coins and those coins whose values are falling.  I've been doing some experimenting with my own rigs and have found 10-15 minutes seems to have the best average earnings per day for my setup (mostly 1080s).

For a ten minute refresh rate, I definitely recommend at least a 10% price switch based on the fact that the process of switching algorithms will probably cost you a minute of mining time by the time the new mining work reaches full productivity.  But ten percent only covers the cost of that lost minute, so it is often better to use a price switch of at least 12% or 15% to make sure it is profitable (rather than just breaking even) to switch than continue mining the current coin.  

You may also want to consider setting a Price Spike Limit on your GPUs to filter out coins whose prices are just too high to be realistic.  Unfortunately, there are a few situations, such as orphan coins and sudden changes in the coin's pricing data that can cause a pool to temporarily provide an inaccurate estimate of a coin's worth.  Not only will the payout be much lower than the estimate in these situations, a lot of other programs will switch miners to these coins simply because the price is the highest, which drives up the coin's difficulty and lowers your potential payout even more. I find it best to just ignore these coins, so I set my Price Spike Limits to be a few dollars of what the average for a GPU usually is. For example, right now for a 1080, I might have a spike limit of $6.00 or $7.00.  That way, there is still flexibility to take advantage of appreciating coin values while not having to worry about wasting time mining any coins whose earnings briefly spike over that amount.

Thanks for trying out the software. Please let me know if you have any other questions or feedback.