started adding these kinds of references, but maybe this should eventually go in its own stand-alone entry:
A kind of 4d Chern-Simons theory intermediated between ordinary 3d Chern-Simons theory and compled 3d (hence real 6d) holomorphic Chern-Simons theory:
Kevin Costello, Edward Witten, Masahito Yamazaki, Gauge Theory and Integrability, II, ICCM Not. 6, 120-146 (2018) (arXiv:1802.01579)
Kevin Costello, Edward Witten, Masahito Yamazaki, Gauge Theory and Integrability, I, ICCM Not. 6, 46-119 (2018) (arXiv:1709.09993)
Meer Ashwinkumar, Meng-Chwan Tan, Qin Zhao, Branes and Categorifying Integrable Lattice Models (arXiv:1806.02821)