I think the scope here is still far too open ended to estimate it or implement it at this point.
Some of the sources of complexity include:
- in topics, we only let people quote from a single post at a time, while in chat, we need people to be able to select multiple messages to quote
- in chat, on mobile, there isn’t any way currently to select part of a message, and long press brings up a menu
There are important details of the interaction design to figure out with regards to the above. We could attempt to do that first, through more discussion here or in a related topic. Or we could assume that has to be done during the implementation, in which case, I think we have to accept that we’ll be discovering scope and making design decisions along the way.
This is probably not an easy one for an outside contributor to land, especially not in one step.