My 2 cents on this: I personally prefer weekly payments, as it's essentially a more fine-grained DCA approach compared to bi-weekly or even monthly payments. Especially when exchange rates are 'spikey', i.e. they change a lot (upwards / downwards) in a short amount of time, it could be beneficial to have a higher payout frequency.

However, there is this fun online calculator which indicates that these two strategies differ just barely, with bi-weekly being slightly superior; we're talking about single-digit or lower percentage differences. I think Bitcoin is just not volatile enough. On paper, whatever we'd save in fees by having bi-weekly payments, would be more significant than any potential gains from shorter payment intervals.

First graph is a weekly investment of $50 from the start of this year:

And here's $100 bi-weekly:

They're almost identical, netting 0.03983BTC vs. 0.04007BTC, i.e. just a 0.6% advantage for the bi-weekly strategy.
If we look at it for just the last 2 months though, it's a bit more significant, yielding 0.00717BTC (bi-weekly) instead of 0.00695BTC (weekly), an improvement of 3%. Do keep in mind that savings through less UTXOs come on top of those 0.6% / 3% gains.