Inline expressions shouldn’t use a wrapper span

[mbostock]

In a case like this…

<div class="grid grid-cols-4" style="grid-auto-rows: 86px;">
  ${modes.map(mode => BigNumber(events[0][mode], {title: mode}))}
</div>

we really want to avoid the wrapper SPAN element so that each interpolated big number is a direct descending of the grid container. Maybe we can do this using document fragments? And comment nodes to denote where the fragment starts and ends?