I do the same thing KalpaI'm up to 12 ELW's 1st discovered. I check the ones close to Sol. The ones further out I'm not to worried about.
I used to worry about this. I am on my first ever exploration trip (again). The first time I was about 5000 LY out when I had the options screen of the game hang on startup and after mashing the keyboard a bit, discovered that it only looked like it had hung and I had cleverly managed to re-set my commander and lost everything. I was particularly worried about the ELW I had discovered. It took some time to build up from the lowly sidewinder to get another exploration Asp and set off again. Fortunately I had taken a screenshot of my ELW so I headed off to it and there it was, still in pristine undiscovered form
I am 11000 LY's out now and haven't discovered another ELW
I am heading for Sag A* and I plot 200LY's at a time always ensuring I have enough fuel to arrive at the end of it and that the destination is a scoopable star. I also headed off at a slight angle and occasionally flip the map to make sure I am not heading in a completely straight line.
When I arrive, I honk, scan the star and pull up the system map. If there are any WW's ELWs or AW then I will usually scan the whole system (I travelled 25000Ls today to get to the damn WW) . Otherwise I'll scan metals that are close by. I rarely do gas giants unless relatively close.
I don't need to scoop as I know that my final destination is reachable and sccopable but I do anyway when fuel looks low, just to be on the safe side.
By the way, are you aware that you can get a clue as to the planet types by the sound they make in the system map?