Anyone keeping permanent overflow inventory at a 3pl warehouse or is that overkill?

My IPI finally stabilized but the whole experience was stressful enough that I’m thinking about permanent changes instead of just waiting for the next crisis. The idea is maybe 60 days at FBA for prime benefits but 90+ days sitting at an external location, drip feeding shipments as levels drop instead of big quarterly sends that spike storage fees and tank metrics.

For sellers running this hybrid setup does it actually reduce stress or did you just trade amazon headaches for 3pl warehouse coordination headaches? And how do you handle replenishment timing so you don’t run out but also don’t overpay storage at both locations?