No. From a tactical perspective, minefields are very difficult to clear, especially in the short term to achieve tactical objectives. That's why they're effective. The fact they're dangerous decades later shows it's not easy.

Interesting. I thought the extended cleanup was because the agent was derived from more stable precursors (binary agent), plus the normal overreaction to 'OMFG NERVE GAS'. But the (not conclusive) Wikipedia says the resultant agent is potent for 'years'. I doubt that kind of chemistry stays potent for that long in the wild, but it's by no means my area to judge. I don't think it changes the strategic or tactical view, but yeah...the thought of a year persistent toxic dead zone is unpleasant.

Even the most long-lasting ones will still evaporate in a few weeks. (Of course, if it's inside a bottle it will not evaporate, and if it's inside a city you probably want to decontaminate it rather than wait).