I know it’s unrelated to the original question, but if it helps, there is detailed information at Itch.io - Uploading HTML5 games. One of the things it mentions is:
Why do we have limits? Although many game engines allow you to export anything as an HTML5 project, often you need to consider what the user experience of playing the game will be like. You can think of an HTML5 project like a website: many of the same performance optimization recommendations still apply. We have these default limits to encourage developers to consider how their games are distributed, especially since it’s so easy these days to drop in prefab resources from asset-stores that siginificanlty increase the download size for the game.
Web dev is not really my area, but maybe it could be better to prioritize optimizing the project to be within those limits, instead of lifting them.
I’m posting this in case it helps OP or future readers alike.