I guess it is okay to put these in the hold in a case when travelling? As long as they are well packed I guess exposing them to what ever temperatures the hold gets to is fine?
Yes. Quite ok.
I would strongly suggest you pack them in a ziplock bag or plastic clip case just in case they leak due to pressure changes. You don’t want to be phero-drenched throughout your trip! 
Traveling in the states I just put them in a ziplock bag in my carry on, take them out, let it go through the Xray machine and put it back in.
I use ziplock bag also. I also wrap my A314 and 30ml bottles in bubbles wrap. I’ve never had any issues. Happy travels my friend.