We definitely see the advantage of Asset Hub as an entry point into the Polkadot universe for CEXs, DEXs and ramps in terms of integration and maintenance effort, which will make it easier for parachains or para-objects to obtain liquidity. From the end-user perspective, it’s best if they only see “apps” and do not have the need to see “chains”. Obviously this is easier said than done 
With regards to the UX and DevEx surrounding XCM on Polkadot, we are hoping to improve this with Ocelloids as a universal solution to track cross-chain interactions. With our latest release of the Ocelloids Service Node and the Ocelloids Client Library, wallets and apps can already use our websocket subscriptions to notify users when their cross-chain transfers are executed on the destination. We also support long-running subscriptions delivered through webhooks to monitor all XCM filterable by sender.
We have a demo app that shows all the necessary information regarding a cross-chain transfer. It would be easy to aggregate the information across all chains and store in a database to provide a UI for ecosystem-wide cross-chain interactions. Of course, this won’t be a full-fledged explorer but users will be able to see if their transfers or XCM actions were successful, failures, and if their assets were trapped along the way.
We are currently focused on XCM but we do plan to generalize to other use cases. We recently decoupled the ingress layer, where block ingestion happens, from the execution layer, where processing, filtering and matching happens. We added support for asynchronous request-response to the ingress which means that by simply connecting with the ingress, you will be able to access both blocks and storage across all supported chains. This will pave the way, for example, to track cross-chain balances, assets and tokens holdings. With the same request-response model, we can also open up the possibility to relay signed transactions without the app or wallet having to directly handle connections to multiple chains, providing a supercharged middleware to abstract away the multi-chain world.
Re: standardization and coordination around XCM, it would be great if there are dedicated spaces for such discussions. Besides the lack of parachains registering their tokens on Asset Hub, we’ve also noticed that despite the introduction of unique TopicIds for XCMs and related runtime tools, parachains have not adopted this (or only partially), which makes correlating multi-hop XCMs extra difficult. It would be great to be able to discuss such issues with the relevant parties.