The fixed installation design could easily be stationed in three locations in Israel, North, South and Middle to provide total coverage. Being such a ridiculously small country, a mobile system is a complete waste of money. Fixed is the way to go for them.
...or even to populated sites.
Scrubbers solve that. And better "toxic chemicals" (can you say gasoline truck?) rolling around their streets in tankers than Katyusha's raining down on their houses and industry...
The Deuterium Flouride and combustion by-products are not serious issues. Residue removal maintenance issues in an operationally deployed system are easily manageable.
The real issue was keeping the mirrors cool. And the fixed installation allowed for an effective approach to implement a solution. One that is not easily translatable to a mobile platform.
Deploy it now. Its better than nothing.