Yes it is, and I have discussed using something based on the TEI markup system for this. In fact some of our texts already support a limited subset of these. However it is not useful so far, as, as you say, it needs to be built into search to be effective.
The good news is, with our next generation translations, since the text and translation are always in parallel, any such markup in the Pali text will work equally well across all translated versions. So if, for example, I am reading in Dutch and I wanted to search within all teachings by Ānanda, this could be done. The technical implementation of this is not so hard, but creating the basic markup will be time consuming. Still, I would expect it to be done within a few years.
Is the “… few year” part right? This is a long time waiting. Having said this said this there might a lot of other issues in the priority list.
Also it might be worthwhile to consider how the URLs may look like now itself so any URL schemes may not have to change for existing backlinks. You can perhaps display an under construction page initially so when the feature is in fact implemented the links will become valid.
Indeed. Part of the current translation program involves segmenting the Pali text, which then provides a URL scheme at a granular level for the whole Pali canon. But we need to be confident in this before applying it system wide. As part of my project I will be checking these segments and ensuring a reasonable level of consistency.
Also following might be a good platform to add this type of annotation: https://hypothes.is/. This perhaps can be done by the community itself if the page URLs might not change. Since this is open source we might be able to request features which might be helpful to SC also.