For strict brand compliance, Plus AI is my go-to. It sits right in Google...

https://touch-wiki.win/index.php/My_PowerPoint_Export_Changed_Fonts:_How_to_Stop_the_Formatting_Nightmare_Before_Your_Next_Meeting

For strict brand compliance, Plus AI is my go-to. It sits right in Google Slides and makes PPTX exports painless. It handles font substitutions accurately, so your decks stay on-brand during the transition