The Nullius overhaul with a curated pack of 24 other compatible mods that provide convenient options without radically undermining normal gameplay. All third party techs are integrated into Nullius tech tree, and all recipes are reworked to use Nullius materials. Subset of the Nullius Maximus Modpack.
The mods in this modpack are chosen to help in specific areas in which vanilla game mechanics can be frustrating during a Nullius playthrough. For example, the belt bus/spaghetti stage can be a challenge due to a large number of intermediates and many recipes with 4 or more ingredients. Miniloader and Bob's Adjustable Inserters help to make belt-based factories less of a slog. Nullius is known for a lot of chemistry, and pipe mods like Advanced Fluid Handling, Pipe Visualizer, and Fluid Must Flow can make a rats nest of piping much less chaotic. Many intermediates have multiple ways to make and use them, so integrated tools such as Recipe Book and Factory Planner are a must for navigating this web of product interactions. Nullius allows you to manufacture new android bodies for yourself and switch between them at will, so Auto Trash is useful to help manage each of your bodies unique logistic requests. Many chemicals in Nullius are derived from nothing more than seawater and air, so a balanced mod to create it where needed like Safe Waterfill is handy. With no oxygen, fuel is a bit more complicated than in vanilla, so a central fuel stop may be more convenient, hence Automatic Train Fuel Stop. Robot Replacer is useful for any overhaul like Nullius with multiple tiers of bots that you will eventually want to upgrade.
Mods in this pack tend not to rely on heavy per tick scripting and thus should be friendly to UPS even for a large factory. If you don't want every mod included in this pre-made mod list, it may still be useful as a shortcut to download and enable a variety of Nullius-compatible mods and then opt out of the pack and those individual mods that you don't want.