The 400uF electrolytic is in series feed to the midrange.Oh, wow! Welp, on the plus side there is more room for sonic improvement. But 400 uF of film caps will certainly need a new layout/board. And it looks like one of the other ELs is 220 uF. And not only much bigger but also $$$.
My new boards were much larger. I compensated in the passive radiator chamber by removing a similar volume of the fiberglass batt. But I only had two 100 uF ELs to replace. 400+ is probably still doable but complicates the issue and makes the upgrade spendy. Clarity CSA 250V is available in 100 uF for $68 each. PulseX 250V is more affordable and should be sonically superior to ELs. Lean on Tom’s Knowledge, Robert!