Can we please extend the limit of this Render Delay from 500ms to something reasonable? It seems silly that I have to add 3-4 separate Render Delay filters to achieve 1500ms delay required for my Elgato capture delay.
Unfortunately, needing that amount of render delay is very uncommon, and there is little chance that we will be increasing the default limit. If you are getting a 1.5s delay on a USB3-based capture device, there is something very wrong with either your PC or the capture device, and you should look in to correcting that instead. If you are still using a USB2 capture device, my recommendation would be to upgrade to a newer device if the current workarounds are not acceptable to you anymore.
To be clear, the Elgato Game Capture HD and HD60 are USB 2.0 devices, and plugging them into a USB 3.0 port will not improve their performance in terms of delay. Elgato devices have so much delay due to the encoding and decoding process they have to go through to fit the video over USB 2.0. If you want a real-time capture card, I recommend getting a real USB 3.0 device. If you want to stick with Elgato, the HD60S or Camlink should work.