Generalized Cluster Structures Related to the Drinfeld Double of $GL_n$

We prove that the regular generalized cluster structure on the Drinfeld double of $GL_n$ constructed in arXiv:1912.00453 is complete and compatible with the standard Poisson--Lie structure on the double. Moreover, we show that for $n=4$ this structure is distinct from a previously known regular generalized cluster structure on the Drinfeld double, even though they have the same compatible Poisson structure and the same collection of frozen variables. Further, we prove that the regular generalized cluster structure on band periodic matrices constructed in arXiv:1912.00453 possesses similar compatibility and completeness properties.