For sure, the transaction history will forever live on the Zcash blockchain, the use case usually targeted for a specific time period, usually following a fund raising or following a planned exchange custody proving - when the traffic to view such history will be high.
I will sync up with the devs and discuss the implementation, it does look out of scope of the grant as we are in the hosting and support phase for the explorer presently.
If you have an interest to extend the features, feel free to contribute GitHub - nighthawk-apps/zcash-explorer: Zcash Block Explorer
Still, we will continue testing & improving the performance for fetching all history of a VK and possible support for NU5 as we await the test-net to be launched.
The expectations will be targeted to align with partner adoption of setting up multiple instances of the explorer and community adoption to use the zcashblockexplorer.com in web & mobile apps for providing accurate blockchain data to end users.
The explorer can handle 1500 user/sec on the Homepage and 150 users/sec when calling the /transactions or /blocks or /address pages. This is with the current infra setup. If there is high usage, we plan to scale up to meet the demand.
Performance improvements will come with maintenance updates via upgraded zcashd software & zecwallet-cli. And we have plans to add minor UI enhancements like realtime tx count updates on tx pages, etc. We will be open to review PR improvements in line with the privacy preserving architecture that is currently setup with the Elixir + Docker framework.
