Usually:

- The broad fee-offset framework is set in the LPA.
- LP-specific variations, clarifications, or extra rights are often handled in side letters.

Not all LPs demand a 100% offset.

- 100% offset is common in some institutional contexts
- But many LPs, especially smaller or friendlier early LPs, may not push for it
- Institutional LPs are more likely to request bespoke economics or reporting through side letters
- Emerging managers should be cautious: side letters can create operational burden and unequal economics

So the market answer is: core economics in the LPA, exceptions in side letters, and 100% offset is not universal.

References:
- https://decilehub.com/base/1-general_questions/163515-can-a-gp-still-use-side-letters-to-give-a-favorite-lp-better-terms
- https://decilegroup.com/articles/raising-institutional-lps