Sorry, I didn't update the assignee field; as I mentioned in a previous message, this ticket is on hold, and I'm not working actively on it anymore. I initially worked on it because it was thought to be an obvious problem with an easy fix, but it turned out it is not.

We could add a configuration option to enable the use of proxies when bytecode enhancement is enabled, I suppose, but that's quite a big change:

1. If enabled by default, this could break existing applications
2. Even if disabled by default, I suspect such a change would have a large impact on lots of places in the codebase, so it would require extensive testing (and by that, I mean a lot of work).

So all things considered, I think it's unlikely to be fixed in 5.x.

It may just be me, though. I'm not that familiar with bytecode enhancement and may have missed an obvious solution. Guillaume Smet may confirm/infirm, at least on the "targeted version" aspect of the problem.