Loudness standards Pond5. How is the mix converted?

Greetings colleagues! I can't find any information about the volume standards for uploaded tracks. I understand that the trend is high volume. But I noticed that after uploading, the preview of the tracks loses a lot of quality and I understand why this was done. I have a dilemma. On the one hand, you can make a track loud -8 LUFS, but it will be converted by Pond5 and lose dynamics. On the other hand, you can make tracks -14 LUFS and this is enough for almost all social networks.
I appeal to everyone, please tell me the golden mean of the volume of the mix.
Thank you in advance!

Good Day! i record with 14 LUFS and my tracks seem to be good on playback. i do leave a little head room for mastering though.

Thank you very much!