Loading a map does not load only the next map alone (and Hydlaaplaza has already much more geometry information and different textures than most other maps), but also parts of the adjacent maps to ensure that you can see the next sector looking through the next map-loading portals (and Hydlaaplaza has a few more adjacent maps than others).
You might switch to "Background Loader: World" in the PlaneShift launcher. Then the adjacent sectors will be loaded while traveling. That means you can probably pass a map-loading portal without a map loading break; but loading breaks may appear anywhere else at sector boundaries, e.g. under the houses built over the entrances to the East Passage, in both directions. Except you walk slowly in such areas, and the map loading process finished in the background already before you pass the sector boundary.
You may probably find this mode rather annoying after a while.