We have had several fields adjusted here (as have many others) and there was no requirement for check strips.  If you are happy with the number they came up with I would challenge the check strip requirement.  Had had to do that in the past on different crops a couple of times.  They are a PIA.  You end up with a strip with weeds you may not be able to deal with because you can't spray or work a 10' strip in the middle of a crop.  Don't know exactly how it all works in regards to check strips but I think the requirement is down to the individual adjustor, company region or whatever.  We raise sunflowers and check strips were common in the past because of the difficulty in determining yield.  Last year we had 1 field adjusted and the adjustor said they are happy with the yield numbers and do not require strips anymore.  I just wish I never had to file a claim in the first place.