I agree there is a case for having external content displayed by default when forwarding / replying to emails, so I am not suggesting changing it.
But there is a user base which is focused on privacy, and this has been increasing in recent times. I think to have an additional option in the client to toggle “block unsafe content” for replying / forwarding would be a great addition, and make emClient even more water-tight for the privacy conscious people out there. I’ll raise it as a feature request on the discussion forum.
Update - I have created a feature request here. I suggest people post there support if they would like it.