Video Previews not helping in render

Did anyone find a straightforward solution to this? 

I'm using Premiere Pro 2023 and working with MP4 H.264 4:2:0  4k footage.
My timeline is fully prerendered, 4 minutes on the timeline took around 8 minutes to prerender. 

Now when I try to export the video with "Match Source" and "use previews" and nothing else, it says estimated time is 8 minutes then it starts to climb up until it says 30 minutes estimated time.

I'm no expert whatsoever but it seems such a needless and trivial issue, since my previewed playback is running smoothly in 4k, I just need to get it on my computer and yet it wants to export nothing for 30 minutes. 

I'm not sure if this will cure the problem for everyone but I have just been suffereing this same problem. Without really knowing what I was doing, I thought I'd experiment. I tried turning off the effects button in the export settings and 'Presto!!!' my render, which previously took around an hour, now renders in about 30 seconds!!

Even when there are no effects selected, if the button is on it makes the render super slow almost as if it is trying to apply a 'non effect'. I hope this works for you guys.

Same problem here, I had a rendered timeline with Video Previews set to Quicktime Apple ProRess 422 HQ, requiring hours to export despite clicking on Match Sequence Preview Settings and having Use Previews checked.

Somehow changing the HDR Graphics White (Nits) export setting from 203 (75% HLG, 58% PQ) to 100 (63% HLG, 51% PQ) made the difference for me (a few minutes to export).

MacOs 12.5.1
Premiere Pro 23.5.0 Build 56.
Project Color Management:
- HDR Graphics White (Nits): 203 (75% HLG, 58% PQ)
- 3D LUT Interpolaion: Tetrahedral

I am facing the same issue on several machines (iMac 2020 Intel, I mac 2019 Intel, Premiere 2022 as well as with l´the latest Premiere 2023).

It is sooo frustarting! You finish your projects and have rendered everything for hours before then you hit the export button (use sequence settings with previews) and what happens, it will render again for hours! This is something which can`t be accepeted from a professional software provider. This  leads to real business problems! I want my money back!

I think the main frustration is that several builds ago, the exports were significantly faster when using previews. Now, and for the last 2 builds (at least) it is much slower. Using the same settings. And according to the official Adobe export best practices, if exporting using previews to the same format as the previews, it should take seconds. But mine takes as long (the exact same time) as if there are no previews.

This is an ongoing issue for me, going back for numerous versions now.  I work in ProRes, render in ProRes, and check "uses previews" on export to H.264, meaning I want it to read the rendered ProRes files to encode to H.264, not go back to square one and re-render everything from scatch into H.264.  Yet it's obvious that it's doing exaclty what I don't want. This is an issue direct out of Premiere or via AME.  Seems like a #bug to me, and it's aggravating.  If I export into "same as sequence", then it's very fast, and then similar to what @RyanSchinneller said, encoding that ProRes file into H.264 is also super fast.  

The use of previews requires of course that the Preview format/codec chosen on the Sequence is exactly the same as the export settings format/codec used, in all details. So that's the first thing to check.

Second, if any significant section of your timeline are not rendered with previews, those areas of course won't get any faster.

And from your post, unfortunately I can't be sure of what applies.

Neil

If the time it takes to export is the same as the render time, it's possible your bottleneck is elsewhere in your workflow. Where are you exporting? A fast internal SSD/NVME or an external device connected via USB?