Can I ask why you would even go electric? These small 4 strokes are amazing. And if your not aware do some research on lithium ion battery fires and the fact they still can’t be recycled.
Lithium battery fires are mostly the result of no-name manufacturers and/or neglectful maintenance/use (or in the case of a tesla, car accidents that rupture cells). Lithiums usually have much better discharge rates and capacity than traditional batteries. Valid point on recycling though. Make sure whatever battery you get has name brand cells in it like samsung, the QA isn't worth the risk sometimes.
All those ebike fires usually are from DIY builds with kits from online, not from established brands like Specialized, trek, etc. I think the same would apply for an outboard, but be warned almost all of them would make you an early adopter in a startup- I'd go with something like the new mercury e-outboard. They've got a brand to worry about and the capital to invest in a solid product.
I think depending on your use case and budget, they can absolutely be a sound investment. This sounds like such a use (limited storage footprint and range). Anything that you'd trailer and I'd step up to a 4 stroke now.
Price can hurt though
