I've never had an inductor after the pump that worked worth a darn so I can't help there.  I have run litterally tons of AMS through Banjo plastic pumps and now Chinese aluminum pumps and have never seen any reason to stop.   Every pump I've used over the course of ten or more years has died due to engine failure, not any sort of pump failure. 

I do have a suggestion for your consideration though.  How about putting the AMS in the nurse tank when you load it?  This simplifies loading in the field a great deal and insures that the ams will have time to dissolve in the water so it can actually do some good.  I always questioned whether it  can really do what it is intended to do if you put it in only moments before the herbicide, at least when talking about a situation such as glyphosate where it is needed to soften the water to prevent the herbicide from being tied up.