"fairly typical run-of-the-mill mid-size enterprise software vendor" - read: boring, maintenance, legacy, but that is ok, I work on such stuff when it pays decent daily rate;
"fully-remote SWEs in the "DevOps" software space (Linux, containers, k8s, yadda yadda)", "higher percentage non-code" - sysadmin, jira queue, SEVs, on-call duty, yaml development, no essential prog lang skill, o'rly you need SWE?
"we're junior-heavy already" - babysitting, scrum;
"haven't even managed to backfill a retirement from six months ago", "the work requires a reasonably deep understanding of the underlying platforms" - seek Sol. Architect or on-board into small area first, legacy can wait;
"take-home technical assignment (~4h) or similar at candidate's choosing" - what? take-home k8s cluster? Maybe better try some gig/probation week, daily rate applies ofc.
I think I would fit, but why I should move my lazy ass off my golden handcuffs just before summer?