Do you plan to commit back to the community your extra graph UX/UI. They look very neat and I don't think it will jeopardize the success of your startup. The reason why I asked about the usage of Electron (or similar) is because they are well known to be resource hungry. Slack went down that route and found themself in a pickle. Considering you are also doing a lot of data manipulation in memory (I assume) this might be very expensive on a React Stack. Anyway, something to keep in mind, don't worry about it right now.

If you are going after individual contributor, I'd spend quite some time figuring out good integration points (ie.: Notebooks), so you are better integrated in their workflow. I'd avoid going enterprise, because date warehouse and data visualization are well solved problem (both in SaaS and PaaS flavor). Source: I led data organization at mid/big companies.