Tick and event timers work more or less the same and should have the same efficiency. Tick and Timers are not particular inefficient by themselves but it is what you do with them that matters. You should think of ways to avoid constantly doing line traces or make the line trace as efficient as possible (limit the length, don’t use multi-line, limit the trace channel object count etc.).
Functions that are very demanding should be moved to C++ if they don’t perform well enough in Blueprint or you could try to nativize the Blueprint.