PAR/PPFD by stage

Hi there,

First time poster but I’ve been lurking around the board for a little while. I’m posting to ask about PAR/PPFD values at various stages of your grow. I know this topic has been discussed but I still have yet to come across an answer to my specific inquiries and still do not fully understand the concept. My understanding about PAR values is that your LED will give out a certain PAR depending on how far from your plants it is (among other factors - like the strength of the light itself) but distance from the light changes PAR value. My question is, aside from issues with heat/temperature, are there any other drawbacks to increasing PAR by moving your lights closer to your plants? What about at various stages of growth - can a seedling only use a certain amount of PAR before they will suffer from nutrient burn or are those two things unrelated? My understanding is that seedlings should get between 100-300 par - will giving my seedling 600 par have negative consequences if I can keep temps on point? And what is max par I should give my plants during the seedling/veg/flower stages?

Thanks so much for taking a look at my post. Any help is greatly appreciated!

Also, if your grow light has veg/bloom switch, is there any way to reliably estimate the PAR of using only the veg switch without using a meter? The manufacturer typically only provides par values for the grow light using both switches. Thanks.