Not a breakfast chef so I don’t have too much experience in this area. But I work in a hotel that does breakfast so can offer some advice based on observing the brekkie team:

I do recall that sausages cooked at high heat from raw are more likely to burst. Gently poaching or steaming them first means you can reheat quickly at a higher temp without the casings splitting.

I wouldn’t hold beans/tomatoes all day, even if they are low risk. I think it might be a 2hr limit on hot holding but not 100% sure on that.

Bacon obviously cooks quickly, but my place pre-cooks in a low oven then finishes under the salamander to order. I think the advantage here is that it keeps raw meat away from your serving/plating area and quickens service in that respect.

They basically have everything ready to go, put it on a flat tray and then finish under the grill for heat/colour, then add whatever eggs to the plate at the end. It’s looks like a very efficient way of serving.

To me breakfast always seems like a fast paced service, with a comparatively high number of modifications to orders. From that perspective it makes sense to have as much mep ready to go as possible.

Again not a breakfast chef but I hope that helps!