Lakes with multiple outflows?

[Hungry Donner]

You can get the appearance of a splits if the two rivers rejoin further downstream; I can't think of any examples with lakes but this isn't uncommon with rivers: Bananal Island in the Amazon immediately springs to mind.

[Hai-Etlik]

You can get the appearance of a splits if the two rivers rejoin further downstream; I can't think of any examples with lakes but this isn't uncommon with rivers: Bananal Island in the Amazon immediately springs to mind.

Fluvial islands are also unstable in the long term. One channel wins, or the island gets eroded away.

[Hungry Donner]

Fluvial islands are also unstable in the long term. One channel wins, or the island gets eroded away.

That's fair, although you can set up a situation where fluvial islands are also typical so even if one erodes you're likely to get a new one soon enough. This really does work better for rivers than lakes though, I suspect lakes that border such regions tend to have substantial wetlands around them.