Hello there Josh,
thanks for caring!
1) I tried to play with "dispTexScale" and "dispTexOffset", but nothing really changed. Note: I edited the cfg with the Notepad, also I made sure to restart Houdini in order to reload the cfg.
2) As you say it seems impossible to do it, but I expected this feature to be already present in the plugin. Would be so useful

3) For testing purposes, I tried to load a super basic substance, only one node ( a checker) and no bitmaps. The viewport is way smoother, but still have some slight stutters from time to time.
4) I tried to clear my temp folder. Problem is that that file doesn't even exist in the temp folder. Also with the super basic substance (without bitmap images) I get the same error.
I might be doing something wrong in my houdini project (I'm new to the software)
I attached the files I'm using, in case you want to have a clear view of what's going on.
Thanks again for the help!
I attached the file I'm using