If you really are getting zero out of the membranes now, that may not be the case later as they age.
I would fit up the resin. If it really turns out long term that you don't need it, you will only buy it once anyway. If it turns out long term you do need it, you will have saved yourself dealing with worse problems.
I would fit up the resin. If it really turns out long term that you don't need it, you will only buy it once anyway. If it turns out long term you do need it, you will have saved yourself dealing with worse problems.