plug-in-displace
the (new) GEGL displace has the option 'Sampler' and Default seems to be 'Cubic'; the legacy 'plug-in-displace' has no 'Sampler' Parameter and I guess it uses 'Nearest'; the Problem is that the lovely 'Warp-Sharp' procedure does not work in 2.10 as it did in 2.8 (in fact it's useless, whether in Python nor in Scheme)