Answer
One mitigation that's helped with this class of issue: in IEE, go to Tools > Options > Advanced tab, reduce the 'Number of Pages' setting, and untick the relevant options under the Display section there. This reduces the amount of client-side page/window state IEE keeps cached in memory, which can help with sporadic out-of-memory crashes on machines or user patterns that push the client's memory/handle usage particularly hard — though it's a mitigation for resource pressure rather than a root-cause fix, so it may not eliminate the issue entirely for every environment.