Volume:
If you try to store an enormous amount of energy, this has always been a safety issue (for example: Rocket science). And although I am always among those first blaming management if something goes wrong engineering is relevant as well.
There is ALWAYS risk to be considered; it's engineering's job to IDENTIFY risks of a particular design, and suggest risk abatement, but MANAGEMENT must comprehend this and provide direction. Take too little risk, and your aeroplane will obsolete itself quickly; too much risk, and it may never get anywhere. There are plenty examples of both extremes. You gotta push the envelope, but not TOO much.
Ironically, in the mid-late-60s, airline managements perceived a marketing risk in buying a 3-engine airplane for transoceanic routes. Would SLF ever accept a plane with less than 4 engines? Of course, 5 decades of experience taught us this is a total non-issue.