Apart from the German firm Hansa Triang Minic were notable for their large range of harbour fittings.
The quay and breakwater sections were durable and very useful.
Some modellers here have made their own adaptions but there seem two big gaps to me.

Narrower quay sections, perhaps half the width of those used by Triang. US naval bases amongst others seem to have narrow quays without cranes etc.

Adaptors to allow quays and breakwaters to be angled rather than just squared off.

Perhaps one of the current manufacturers could offer these. If you already do sorry to have missed you.