100% To be fair to the chat agent, I was transferred so they were not the typical front-line agent that quotes you a set of flights totally different from what you requested.

The X team was helpful in confirming this morning that this surcharge was in fact accurate and there is no way around it when converting to a prime flight (no way to break out the short haul from long haul). They confirmed that it was not due to the instant upgrade.

I honestly think a big part of this is the opaqueness of how SWUs work on BA in terms of the fees as it seems like it has been all over the map based on this thread. I’ve only used them to go from J to F on BA where those surcharges are already the same.