Yes, 100%. H.264 can be a nasty format for older machines, but many newer machines have the ability for some sort of hardware H.264 decoding. With that said, when an H.264 video is created, to squeeze out a smaller file size, some frames are full images (key frames (or i Frames)), and others are B frames or P frames (predictive frames, compressed data, not a full image). P frames and B frames are resource heavy when decoding. And when you jump to random parts of your video clip, if you jump to a P frame, your computer has to essentially, look back to the next keyframe before it, then step through all the p frames after to compute what that specific p frame actually looks back – hence a noticable delay.
If you make every frame an i frame (or key frame), your file size will be bigger, but there’s less work that your computer has to do to display that image. (Less guess work we could say!?)
All that being said, when I switched from my 2015 Macbook Pro to a new M1 Max MBP I converted 8TB of video (HAP, Apple Intermediate Codec (AIC), ProRes, PhotoJPEG, etc) down to 3TB of H.264 and put it on a fast external SSD. There are pros and cons to this, but for the most part, this machine has no issues with H.264, and most of these clips are all sorts of video resolutions, most 1080p or under.
I’ve been using VDMX since 2009, and my advice to most users, is test out the codecs with your hardware and find out what works best for you. Back in the day, HAP and H.264 weren’t even a choice, and for my 2015 MBP that still works, I still keep those old VJ drives with the HAP and AIC VJ clips on it because those perform best for that machine.
(Sorry for the long response, but hopefully this will help someone troubleshoot their own VJ setup in the future).
More about I, B, and P frames: I, P, and B-frames - Differences and Use Cases Made Easy - OTTVerse