Variable volume wine fermenters

Im wondering if anyone has experience with these in winemaking or cider making. I am interested in getting one for my home cider operation, i usually make around 100 gallons each year and am tired of plastic and transferring from carboy to carboy. My idea is to have a pair of 50gal ones or a single 100gal with conical bottoms so racking is unnecessary and with the variable volume lid i can pour off some and bottle or keg as needed. Not worried about price i know what im getting into.

My concerns are that the fermentation of the cider is more active than wine. This is why beer guys dont use them do to excessive krausen and over active fermentation that requires blow off tubes. I have never made wine before but i assume that pressure is made during the primary fementation but not sure how much compared to cider. My cider never really gets too active compared to beer. I dont want the pressure to be too great for the lid which is held in by a small air tube seal around the lid. I believe they have airlocks but will this be enough? The wine guys just keep the lid a couple inches off the top of the must to have extra air space until fermentation is done than it is lowered. Any experience or advice would be great. :cheers: