alright. Just limit the size of the stack as much as possible.
There are also some settings to check for increased performance of SNAP - could be worth a try.
- S2 export into tiff - NaturalRGB or Falso color infrared RGB
- S1 TOPS Coregistration error - Java heap space error?
- Problem creating image from a band
For PS processing the stack should contain all dates at once so your only option is to limit the area and to increase processing power.