Rendering issues with Beta 3

I am having rendering issues with Beta 3. For example:
1. Last week one project failed to render multiple times in a place where there was a fusion title with a transition. The fusion title was copy and pasted from an older project. To solve I recreated the title.

2. Yesterday I was rendering a timeline who a clip with a simple speed ramp and while rendering the updates where just showing the speed ramping clip for all the clips and the render would seems to progress but fail towards the end. Solution was to change the motion estimation mode from Speed Warp to Enhanced Better.

Speed Warp is very demanding. Being unified memory, 16 GB might be a bit tight.
How long and which resolution is that clip? I had to render a few Speed Warps recently, the longest one being 18 minutes, but only HD, and my machine was stable.

Clips were GoPro 8bit HD, Timeline about 25 mins long, switched project setting to 4k before rendering.

I'd render the HD resolution in place or as a master file, then compress to H.264/265 separately.