How and where to store database for chrome extension?

Question

Google Chrome

How and where to store database for chrome extension? At first, I just used tampermonkey scripts and stored it in localstorage, but the size there is very limited, if I correctly counted about 4mb in total, this is very small, if you use websql, then 5mb is not much there either, there is also IndexedDB, there is 50mb.
MB for extensions is there something larger?
I need to store the id of the viewed elements, according to estimates, there are already 5 mb in 3 months.