I am now resuscitating this long dead thread with an even more recent update. McSnazzy's solution worked perfectly... up until using the time jump. Time jump seemed to do absolutely nothing in game for me. So... I did some testing.
Each habitat (and likely each object in game) seems to have each aspect of it stored in a section of memory with the interesting part being that all aspects of it share the first 8 characters/numbers, with the last 2 denoting what the aspect is. In my case, build/upgrade timers all ended in 8C and coin generation in A8. Since they share the first 8, you can easily find the coin/gem generation from knowing the build timer.
Since you can set the number of gems and freeze it the same way you can with coins on a habitat, all you have to do is fuzzy search for the timer while building the elder habitat. Once you have that number and complete the construction of it, long press on the line and tap "go to the address xxxx". Scroll through the list until you find the entry that correlates to whatever your typical coin generation ending is, set the value and freeze, and collect gems to your heart's content.
