As a magazine editor, I can tell you that we appreciate it when those with higher tier rejections try us again.

I still think trying the print is better in this case: usually, the 'quality' difference between online and print is not all that high. If they accept a piece, I'm guessing they'll let length, formatting requirements, other pieces in the same issue decide whether they will print it online or print, more than a qualitative difference. Print is able to hold reader attention at greater lengths: reading longer stories online is simply not very viable.

Since you've tried them various times and been given higher tier rejections, I'm willing to bet that if you ask them straight out about their policy, and whether applying for online will make a difference, you might just get a straightforward response.

IMO, if they liked your piece enough to publish it in some form, they would have published your print sub online if the word count was within their limits, but that's only my guess.

Hope this helps.