After a bit more searching I have come across some more threads on this topic:
I am aware that sending multiple pictures in one MMS reduces the quality, so perhaps the best solution is a camera / photos / attachments button in the Messages app such that you may quickly select from recent pictures to send, similar to how the “competitors” do it with an attachments icon in the compose message field of the SMS app. At least this way, even if only one picture can be sent at a time, you can still quickfire a couple off without leaving the one screen / app.