MapArrayReader (#2484) (#1699) (#1561)
It's quite a coincidence, but we've been hit by this very problem and spent some time on it. We created a small project to show how to reproduce our issue and just found #2484 as we were about to open our issue.
Thanks a lot!
Benchmark runs are scheduled for baseline = f3afdd2 and contender = c34f07f. c34f07f is a master commit associated with this PR. Results will be available as each benchmark for each run completes.