This mod allows pack makers to limit the time that players can spend in foreign dimensions. Well, not exactly...

Mod mechanics:
1. Players are able to mine for Dimensional Ores (or kill Endermen to obtain Dimensional Shards) which can be used as a time resource
2. Players are able to craft the Obsidian Cauldron, which allows creation of Coal Coke and Crude Iron
3. Using Crude Iron ingots, players will be able to craft the Steam-hammer, which is used to obtain Dimensional Shards from Dimensional Ores and to crush Diamonds for Diamond Shards
4. Using Diamond Shards with a couple of Dimensional Shards in the Obsidian Cauldron will result in Bionic Eye - the device which allows players to see remaining time.
5. Now it is time for the Time Battery crafting!
6. Next, players will need to craft the Time Machine and a Shard Processor. Place them next to each other and fill Shard Processor with coal, ender pearls and dimensional shards. Newly crafted Time Battery goes into Time Machine (apply redstone signal to it to open storage case).
7. Drain some time from filled TIme Battery and you're good to go into Nether or The End or any other dimension!

See config file for detailed configuration possibilities:
1. Blacklist or whitelist the dimensions which will be "foreign"
2. Enable or disable Dimensional Ore spawn in per-dimension basis
3. Enable or disable Dimensional Shards drop from Endermen
4. Allow or disallow "safe return" upon death in a foreign dimension
5. Set initial spawn point in any dimension

My video walkthrough (sorry for my accent ;)):

You're allowed to include this mod in any modpack you'd like.

This mod development is sponsored by Apex Minecraft Hosting