> and you pre-allocate that address space The increase in stack usage is highly unlikely to require more space than the default 'reasonable' stack size already

> and you pre-allocate that address space The increase in stack usage is highly unlikely to require more space than the default 'reasonable' stack size already being allocated for threads in 32b environments where one is likely to be operating v8; typically the defaults are already pretty generous. Unless the default thread stack size allocation actually has to be increased to accommodate the modest growth caused by the change then there is zero impact on available heap.