Very cool. I appreciate that the mat’l isn’t being yanked directly from the wild & you’re sweating good.
Edge plantings(both in & out of pond) will help but there’s that delay for maturity.
Maybe visualize the “natural” inlet source…e.g. stream, waterfall, spring-fed, etc & work from there.
Making a smooth slope on one edge(like at the beach) might be really nice looking & invite more critters but has no overflow control.
Water cuts gorges & sheer walls exist but sloping valleys & flat-as-hell places also have water.
Fun stuff.