You don’t say how large they are (i.e. how long a layer takes to print), nor how many you wish to print at once… but those are important considerations.
First, though, if it t’were me, I’d stick with PLA (time to heat up and cool down the bed is much faster than the hotter temps required for ABS). I’d also go with as large a layer height as my nozzle size would allow – 0.35 for a 0.50 nozzle for example.
It’s worth figuring out how much skirt you’ll actually need – check this by watching the second print (so that you account for the filament that’s withdrawn when a print is finished). Small parts may need 3 or 4 loops around for the skirt, larger ones only one loop – these take time and if time is of the essence, don’t waste either time nor filament on the skirt.
Print speed can be tweaked, but in my experience, it’s a really iffy business. Depending on the exact filament, and sometimes on the ambient temperature, and sometimes on the roll of a dice, you can get away with a significant speed-up (change the settings in your Cura profiles). The Lulzbot profiles are pretty conservative – so a small tweak will probably be ok. I wouldn’t expect that doubling the speed, though, is going to work…
Finally, you need to consider the time to print the smaller layers – the slicer will ensure that the filament laid down at the start of the layer is cool enough that the next layer can begin. If the layer is small enough, the slicer will slow down the travel speed for that layer, or just pause, in order to ensure that this is the case. So, if your object is small enough, you can crank up the print speed but Cura will just slow it back down, or add pauses anyway. One way to fix this is to print multiple small objects at the same time – this ensures that there’s effectively enough time on each layer so that the artificial slow-downs don’t need to be done.
I’m sure there are other tips and techniques that can be used; these are just the things I’ve messed with. Although, in my experience, the best solution to long print times has always ended up being patience.