Does PikPak limit WebDAV speeds?

PikPak does not apply a dedicated speed limit to WebDAV. However, WebDAV is a Connected App and uses the Connected Apps transfer quota.

All Connected Apps share a Downstream limit equal to 25% of your total valid monthly Downstream quota. If this limit is reached, WebDAV downloads and streaming slow to about 100 KB/s until the applicable quota resets or the limit increases.

Free accounts also have a daily Connected Apps Downstream limit of 5 GB. The daily and monthly limits are checked in parallel, and reaching either one causes the same slowdown.

WebDAV uploads use the separate Connected Apps Upload limit. If that limit is reached, further uploads are blocked instead of slowed down.

Usage in the official PikPak apps is not affected by the Connected Apps limits. See What is the Connected Apps quota, and how is it different from my monthly transfer quota? for details.