How to disqualify a user from a trait (without FTP)?

[#1]

Our organization uses the DCS API for on-boarding of CRM data (for various reasons, we're not permitted to use the AAM file transfer mechanism).  DCS is fine for qualifying a user for rule-based traits, but how can we disqualify a user?  For example, suppose we have a trait User Gives Consent for which a given user is qualified and later that user withdraws their consent.  To comply with GDPR rules we should disqualify that user within 72 hours.  But how?

If we limit our User Gives Consent trait to a lifetime of 72 hours then okay it'll expire, but then we need to keep refreshing the trait needlessly for all those (possibly millions) of users whose consent doesn't change.  This seems like a brute force solution.  Has anyone else got a better idea?  I did hear rumours of a DCS API upgrade coming in 2019 that would include a trait disqualification feature.  Here's hoping! 

[#2]

Indeed, I suspect the AND NOT combinational logic won't solve the problem either...

1. Let's assume we have defined opt-in and opt-out traits with indefinite lifetimes.
2. Let's assume all visitors start off qualified for the opt-out trait (meaning that consent has not been given).
3. Visitor A gives consent and now qualifies for the opt-in trait also.
4. Visitor B refuses to give consent.
5. Segment rule (opt-in AND NOT opt-out) -> segment of size 0, so this doesn't help.
6. Segment rule (opt-out AND NOT opt-in) -> segment of size 1, containing Visitor B.
   Note: This segment definition could just as well have been (NOT opt-in) since opt-out is always TRUE.
7. So, we could use the second segment rule to come up with an exclusion list.

But as Andrey pointed out, suppose a visitor changes their mind and they revoke their consent.

We've got both traits qualified for Visitor A and we can't undo that (at least not through the API).

Any more ideas?   - Hugh

P.S. Surbhik, the original question was how to do this without FTP file transfer but rather in real-time.