Warpdrive is probably the best mod for modpacks due to how highly configurable it is. Unlike Galacticraft and Advanced rocketry where its just Select Destination, Press Button, then Go To Another Dimension you can build a fully custom starship and jump it around space. However, its not a mod that can just be tossed into a pack and used. While it does have an automatic config file for use with Galacticraft, any other dimensions would have to be manually added. But all in all as a modpack creator it is worth it.

It’s Startrek in Minecraft, what’s not to like? You can build spaceships and physically fly them (ok it’s more like jumping) around space and land on other dimensions.

More of a pack utility than a plug and play mod, since you have to set up the configs for space and planet mapping yourself.

Only downside is that certain things like unusually coded blocks, multiblocks, etc often are not supported. Best case scenario, they break every jump and have to be reassembled/ or placed again. Worst case, your world gets corrupted. Rotating your ship is a bit iffy at times too, and has even less support for modded blocks. Best to test blocks on a superflat test world, and never rotate your ship when jumping. But otherwise a really freaking cool mod.