I support your observation that there is an urgent need for new theories of change and especially for different approaches to synthesis. Examples from my practice:

1. Synthesis: http://sdeval.splet.arnes.si/files/2020/06/Sample-Ch-2-Aggregation-problem-Radej.pdf

2. Social integration: https://www.fuds.si/wp-content/uploads/2019/03/rsc_volume_10_issue_2_may_2018_1.pdf

3. Innovation policy: https://sdeval.splet.arnes.si/files/2022/12/sde_DZ_1-15_Measurnig-Smartness-of-innovation-policy-30jun2015.pdf

4. Cultural heritage: https://www.sdeval.si/2017/12/05/smart-heritage-policy-delovni-zvezek-let-x-st-1/

5. Inclusive or rational participatory evaluation? ( fortcoming): https://medium.com/p/5d64c10ac8f6