I don't know who are "they". If you mean the manufacturer (smartdevices/hhtech/whatever), then I believe they do not, and they are happy with compile time selection of device.

If you mean Mer developers, I think that I am the most interested in working on the kernel, and it is in my plans to get the same kernel working on both platforms. But I do not have a Q7, and I don't even know if the Q5 kernel source we have really works on Q7, or is only has some preliminary support.
Even without this work mer can work on Q7, either with the kernel that comes on the device, or with the source we have compiled for Q7 (or with source for Q7 assuming we can get it, if it is different).

I think discussing the Q7 in this thread makes sense, so it is reasonable to ask the thread starter or a moderator to rename the thread.