I'll start with saying I like the additions to WebStorm 2020.1, good job!
However in my case the indexing task became much slower. Now it takes over 10 minutes (less than 3 minutes on WebStorm 2019) to index a monorepo with 50 projects. The monorepo uses pnpm as the package manager (it links packages instead of copying). I cleared the cache fully after upgrading from WebStorm 2019.3.
I'd be grateful if you could take a look at it