Resolve 16 Beta 3 - Small niggles and suggestions

Loving Resolve 16 Studio Beta 3 so far. Few little niggles I've come across though so far (plus a few suggestions):

1. Duplicating a clip/timeline in the Media Pool doesn't always show the new clip unless you click out the folder then back in. This is especially true when using the timeline filter option.
2. Some interface elements (scrolls bars, keyframing etc.) are still too small for 4K monitors
3. Some M4A files import but are silent (problem seems random)
4. Even though now you have the ability to set up timelines of different frames rates, there's still the little problem of not being able to change the master project settings if you get them wrong and have already imported footage. You have to delete everything to change the setting
5. In Fairlight, when enabling the separate preview window, occasionally the video playback will act like it's taken speed. The audio plays at normal speed but the video goes a million miles a second. It corrects itself shortly after
6. 4K50p/60p footage poor scrubbing performance on high-end systems (H264 footage tested)

Suggestions:
1. Ability to access Dynamics from with the Edit tab by clicking on the mixer (saves having to go into Fairlight to use the mixers there).
2. Betting scaling of interface elements for 4K+ monitors
3. Ability to add audio cross dissolves from within Fairlight (seems a strange omission).
4. Better control over delivery codec options - for example, presets are nice, but at times I would also like to specify a maximum/target file size (e.g. 4GB or less for FAT32 USB stick delivery). I would also like to know what my maximum, target and minimum bit rates will be and finally, a predicted file size for everything. This is the only thing I prefer with Adobe is their Media Encoder controls (not the speed, they suck).
5. In Color tab under the Window (mask) options, it seems redundant having shapes already pre-populating the box when only just above, you can click what you need (e.g. linear, circle, polygon). I think the window below those options should be blank and only list what mask you have created, not ones it thinks you might want (defaults). It's confusing.

there's still the little problem of not being able to change the master project settings if you get them wrong and have already imported footage. You have to delete everything to change the setting

No you don't. I just changed the Master Setting from 720 to 1080 in a project. It worked fine, though I did have to rework my Scaling and Position keyframes.

6. 4K50p/60p footage poor scrubbing performance on high-end systems (H264 footage tested)

I always recommend using Optimized Media for H.264/5 originals, preferably Cineform. The performance will always be better that way.

It's frame rates you can't change, not the resolution

there's still the little problem of not being able to change the master project settings if you get them wrong and have already imported footage. You have to delete everything to change the setting

No you don't. I just changed the Master Setting from 720 to 1080 in a project. It worked fine, though I did have to rework my Scaling and Position keyframes.

Got it.