第一段：

Open-source platforms allow for greater flexibility and freedom when it comes to designing, adapting, and using block chain technology, and the overall value of a given initiative increases in line with its potential to scale beyond the local or even national context. And though value may increase, it is vital that accessibility remain low; since so many of the issues to which block chain technology can be applied affect the poor with disproportionate severity, it is essential that affordability is not a barrier.

最后一句的意思是这个技术会导致贫富不均，所以支付能力不能成为一个障碍？

【答】it is essential that affordability is not a barrier.

【翻译】支付能力（购买能力或负担能力）不应成为障碍，这是至关重要的。

第二段：

Even in settings where a block chain may be appropriate, such as the ones put forward in this paper, it would still be necessary to decide between different variants.

这句主要的疑问是“decide between different variants”该如何理解？

【答】decide between different variants：

【翻译】在不同的变量之间作出抉择。

decide between... 在两者之间做出抉择(或决定)。例如：

He had to decide between surrender and starvation.

他不得不在投降和饿死之间做出抉择。

第三段：

But it’s when we consider how these benefits combine that the technology’s truly transformative potential is revealed.

但只有当这项技术的革新潜能真正发挥出来的时候，我们才能考虑如何将这些好处结合起来。

这样译法有没有问题？

【答】不正确。你把主、从句翻译颠倒了。这是一个强调句，被强调部分是时间状语从句when we consider how these benefits combine。我们把it’s...that...去掉，就是：

But when we consider how these benefits combine the technology’s truly transformative potential is revealed.

【翻译】但是，只有当我们考虑到这些益处是如何结合在一起的时候，这项技术真正的变革潜力才被显现出来。