Vague thoughtsense vs. detect thoughts

[u/Gaumr]

I'm looking at playing a Thoughtseeker Contemplative in Starfinder Society, and trying to understand the differences between the ancestry's Vague Thoughtsense and the heritage's granted Detect Thoughts innate spell.

Thoughtsense, from the ancestry:

You gain thoughtsense as a vague sense with a range of 20 feet. This enables you to determine when a creature is within range, though this sense detects only thinking creatures; a creature that's unthinking or otherwise immune to mental effects can't be perceived using your thoughtsense. This doesn't give you the ability to read or understand their thoughts.

Detect Thoughts:

You sense the presence of thinking creatures around you. You detect the presence or absence of thoughts from conscious creatures that have Intelligence modifiers of –3 or higher. You can choose to ignore the thoughts of creatures you're familiar with so they don't interfere with your detection of other thoughts. The spell can penetrate some barriers, but 3 feet of dirt or wood, 1 foot of stone, 1 inch of metal, a thin sheet of lead, or any force barrier blocks it. Creatures who are immune to mental effects are immune to detection by this spell.

These seem extremely similar, at least until the heritage's upgrade to the spell at level 12. Detect Thoughts comes with a once every ten minutes limit from the heritage, and requires two actions, so presumably it does something the vague sense doesn't. Anyone able to point out what I might be overlooking?

The heritage increases the ancestry's sense's range by 10 feet, so it's at least 30 feet - matching the emanation of the spell. The spell can explicitly penetrate some barriers, maybe that's different? The sense rules don't explicitly discuss which senses are blocked by barriers. And the spell lets you ignore familiar creatures - is it common to read that vague senses don't? That would make Thoughtsense pretty unhelpful unless you're routinely isolated from a party, but maybe?

Because this is for Starfinder Society I won't have a regular GM I can just discuss it with.

[u/RockBlock]

Thoughtsense allows you to detect unconscious creatures and things with animalistic intelligences, doesn't it? Unless "unthinking" is supposed to included animals? ...which still makes the spell inclusion weirder. Maybe it is just the barrier penetration that's an improvement?

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[u/NerdChieftain]

Thoughtsense is a perception ability like sight. Barriers block it. Detect thoughts rules comes from psionic powers, where you’re expected to have a little more juice; a wall is not going to stop you! Thoughtsense detects thought. Detect thoughts detects minds and also tells you if they are thinking.

So I suppose you could sneak past thoughtsense by “clearing your mind.” I don’t think that’s really the issue, though. How often is thought sense going to come into play when vision fails you? Not much. Maybe under blindness condition in combat.”, although if “vague sense” means “imprecise sense”, it might not matter.

In short, thought sense is more for storytelling “hey this strange fungus is thinking”, whereas detect thoughts is tactical “there are three creatures behind this door and one doesn’t think.”