This aligns with the emerging literature. The STEP-HFpEF trial and several smaller studies have shown that when adequate protein intake and resistance training are maintained, the proportion of weight lost as lean mass can be reduced from the typical 25-40% range down to 10-15% or potentially even lower.
The key variables appear to be: protein intake above 1.2g/kg/day, progressive resistance training at least 3x/week, and avoiding excessively rapid weight loss. You hit all three.
For anyone reading this who's NOT currently doing resistance training on GLP-1 therapy — please start. You don't need a PPL split or anything complicated. Even 2-3 days per week of basic compound movements will make a meaningful difference in lean mass preservation.