The GARCH-MIDAS applications are gaining ground in the recent literature.
See, for example, among others:
Wei et al. (2018). Hot money and China’s stock market volatility: Further evidence using the GARCH–MIDAS model. Physica A: Statistical Mechanics and its Applications.
Pan et al. (2017). Oil price volatility and macroeconomic fundamentals: A regime switching GARCH-MIDAS model. Journal of Empirical Finance.