The only problem with mosfets is they leak voltage. On my system when the bms activated, they didnt completely shutoff, they still read about 11.7 volts but will not accept current. The controller seeing a 11.7 volts see's a depleted battery and tries to force a charge on it, this caused voltage surges as the bms won't let current to flow. The controller will cycle back and forth trying to charge the battery, I see voltage as high as 20 volts.
Relays or contactors will work, since I use a small 240 watt system, all I needed was a small 12 volt 30 amp automotive relay. For my 12 volt system it works good. Larger systems and higher voltages will probably need contactors.
But the best method is to try and not to reach a situation where the bms will activate but even when I made fine tune adjustments to my controller bulk voltage, there were situations where the bms activated.