WordPress Comments vs Custom Table

Hi

I have been reading into WordPress comments and performance in the front end when calling a large number of comments. I know there is ajax and lazy load options but I was just wondering if I was to create my own custom comments table to manage comments and replies (for a custom post type), would it help with front end calling and performance speed vs using the default WordPress comments? as metabox caches calls etc so this may be one benefit?

I do realise its a vague question as it all depends on the level of data etc but just researching before I start to build and want to make sure I choose the correct option for website speed purposes.

Thanks