In this Adobe forum post I explain the “Adobe Tick,” a strange unit of time used in PREL (Premiere Elements XML Project) files. It may also be used in other Adobe files, as it seems to be Adobe-specific. I originally found the article when I had the same question, but when I discovered the answer I posted this reply (as expertmm):
https://forums.adobe.com/message/8094139#8094139
To summarize, 254270016000 / frame rate is the value that should be used for VideoFrameRate when generating an SQPRESET (Adobe Premiere Elements Preset) file.