The basic concept is the same regardless of material used and specific temperature. You want to keep bed temperature as low as possible without creating adhesion issues. In fact, I've seen a lot of people with Ender 3s who have to choose between poor adhesion and elephants foot. So they compromise and keep temperatures low to avoid the elephants foot but use glue stick to solve the adhesion problem. The main cause of elephants foot is the bed temperature being so high that as new material is added over the course of the print, the lower layers are still warm enough that they squish down. An easy way to tell if this is your problem is that your first couple layers go down properly and there's no elephant's foot, but you come back near the end of the print and you have developed it. Obviously the bed is too warm.
Level like a fiend, use a feeler gauge if you have to. There is a big difference between levelling enough that you can print successfully vs levelling accurately enough to stop elephants foot.
Springs may affect how often you have to level but they have literally nothing to do with how level your bed is/quality of your level job.
I don't print in PETG though. It's not worth the trouble for the marginal improvement over PLA. If I need strong I move the printer to the garage and print in ABS and ASA. So if you have zero elephants foot with PLA, but you do with PETG, it may just be a thing with your PETG filament. In that case ignore everything I said!
