I don't understand your post in part--you will be doing research during your study abroad right? So why are you saying 2-2.5 years vs. 1.5 years of research? In my FAQ I don't make a mention of "continuous" research experience for a reason. That's not important to me, and sometimes diversity of experience can be a good thing. I assume you're not burning and bridges and you can resume research at your home lab when you return. It sounds like a good opportunity to me.