The farm I am on has both OSR and a main season crop of field beans. The following timings are of course geographically dependant, but this is how my season panned out for OSR & FBean
OSR came in slowly this year from about 3rd week April with full flower 1st week May, by 3rd week May it was effectively over.
Field bean overlapped it this year, first flower was 1st week May but it was really 3rd week may before it came in fully, it was still going well until 3rd week June. There was a very strong flow from the bean, stronger than the rape in my opinion. Not sure on varieties grown.
The bean and rape most definately overlaped because this years early honey has not set rock hard and white (aka high rape content) but instead has a yellowy/milky colour and remains soft set (consistent with flower and pollen observation). There was also a very strong Willow pressence this year (early April) based on pollen brought in but I dont think you get a particularly strong nectar flow from Willow so I am discounting that as an explanation for the early honey character.
As for moving, I had no need, all within 750m of the hives.
Addition:I know that my girls were working the bean, all of it was in one direction from the hives 'hard right' as they exited, and they did. Pollen colour also confirmed that a lot of that was coming back; no reason not to believe that nectar was also being collected. R