I just looked at the ZX Spectrum Vega Plus project, they planned delivery in September 16. As we all know, building custom hardware with a small team is very difficult, so they may be honest.
Their backers are very hostile, they would not motivate me to work faster.

Starting another campaign in this state does not increase my trust in them. They may plan to use the funds to finish the ZX Spectrum Vega and the revenue from that to fund the Gemini.

I would suggest waiting. The project is funded, so they will start and in the worst case one will get the device one or two months later then the backers.