Load screens and opening a level with blueprints

How do people manage their load screens and opening levels?

I'm currently using the async loadscreen plugin to easily call a loadscreen on loop when ever something is loading. This is generally working apart from a few issues.

My full setup at the moment begins with the build opening a "main menu" level. This is empty and just calls a UI that at the moment just as an enter button. When clicked it uses the "open level" node.

Here the main level is opened and async does it's thing. But when the main level is loaded the shaders are compiling when you spawn in and the exposure has to adjust to the lighting. I can't find a way to delay this to let it settle before the loadscreen finishes as it seems as soon as the open level node is called everything after that doesn't fire off. It's binned.

The other issue is when I stream the project via pixelstreaming the async loadscreen freezes for 30 seconds or so before continuing, this doesn't happen with no load screen, it takes about 5 - 10 seconds with a black screen.

When I Google about using loadscreens either it's the plugin I have or a fake loadscreens where people call a widget, add a delay and then open the level. Which doesn't make sense because if the open level is large enough you hit a black screen where it's actually doing the loading.

It's more of a walk around arch vis project but I want it to load in smoothly and start with shaders compiled.

Is starting with an empty main level menu a bad idea? I did it to try and speed up the initial boot time and to not interfere with anything in the main level.

Any advice on where to look up on these things to solve freezing or delaying loads to let levels settle?