If you do that the raft will have less strength to resist the layer above contracting.
If your raft isn't stuck well enough to resist its own warping forces, how is it going to keep the object flat?
Sometimes I get the loops at the end lifting if my head is too high but that happens as the raft is laid, rather than when it cools.
A pause at the end of each raft line to give a blob might be a good idea. I saw a video of a machine (IIRC a makerbot) doing that (due to segment pausing I think) and it occured to me that it might be beneficial.
If your raft isn't stuck well enough to resist its own warping forces, how is it going to keep the object flat?
Sometimes I get the loops at the end lifting if my head is too high but that happens as the raft is laid, rather than when it cools.
A pause at the end of each raft line to give a blob might be a good idea. I saw a video of a machine (IIRC a makerbot) doing that (due to segment pausing I think) and it occured to me that it might be beneficial.