I did some testing with Ignore Gene Strength, and it seems to ignore only your creature’s GS.
I loaded a game without ignore GS, and went to nether lv 50. On average, enemies had about 10k HP.
Then I loaded a game with ignore GS, and enemies had the same 10k HP on average.
Then I tested taking attacks with a level 1 creature and charms. Again, in both scenarios, the average incoming damage was similar.
With a 500 GS difference, there should have been noticable stat differences on enemies, but there wasn’t.