https://iotdiy.com/what-are-the-differences-between-broadlink-products/ Only difference seems to be the support for HTS2 Temp & Humidity in RM4mini and RM4 pro. Also there is one video comparing these in Arabic مقارنة بين جميع اصدارات اجهزة برودلينك - Broadlink RM 4 PRO VS RM 4 MINI VS RM4C - YouTube
