With ereswap you have 2 swap partitions, one on eMMC for backup and one on the SD card for main usage. When ereswap refresh the swap it put on the backup, put off the main and then backwards, put on the main, and put of the backup. These are 4 steps and 2 data movings, using backup swap for the transition.

If you would have 3 swap partitions you would have eMMC one for backup (only if you haven't the SD card or it's broken), and two in the SD card to alternate. When you want to refresh you just put on the swap2 and put off the swap1, and thats all. (Next swap refresh you will put off swap2 and put on swap1). Backup eMMC swap is never used (saving of damage his cells and damaging SD ones) and you only need 2 steps and one data moving. And 2 swap partitions share the damage to sd cells.

I prefer the second method and I will try to modify ereswap to use it. I hope Estel likes the modification and integrates it in ereswap. Maybe could be make an option to use one or two swap partitions on SD Card, as user wants.