Several posts of late address the shailo of an intrusion into a reish or daled from the left side (not lamed from line underneath which is more chomur). I asked Rav Friedlander Sh' as to when we have to be worried about this. His response was that it's only really a problem if it is an abnormal intrusion, in his words a "vildeh" stroke that sticks into the letter before it much more than usual. he said for example, a beis, which has an ekev of two or more kulmusim and most of that is sticking into th eleft of the reish or daled, then it woul dbe problematic. But a regular ekev which sticks in slightly, or even a bit more than slightly would present no problem.
I believe sefardim are more machmir in this but I am unfamiliar as to the practical guidelines.