This impacted our company and we had to do the same rollback.
we went from 1.6.x to 1.14.0, the next work day jenkins became unresponsive under load, and our jvm monitoring told us that the blue ocean rest computers endpoint was using most of the cpu time.
We rolled back to 1.13.2 and disabled the Blue Ocean Executor Info plugin and our Jenkins master is far more responsive and page loads for blue ocean are much lower.
Our builds have 3 stages, the first one is a single stage, the second one has 3 parallel stages, and the third one has 50 parallel stages, 32 of which are computed dynamically and launched with the "node" step.
Please revert the change to make the Blue Ocean Executor Info plugin a required dependency. I'm sure it would be okay on a smaller system, but for a system like ours it is untenable.