Safcon wasn't as much of an issue back then. Now, on the other hand, with primarily IS enemies to consider, they're increasingly unlikely to get it.
Sure. That may be the case
now, but the Clans are hardly ones to adapt quickly or be very forward thinking. Cray has speculated on how their society is very inefficient and counter-intuitive for growth (A clan that spends resources on expanding to a new colony would then lose it to a Trial of Possession from another Clan)
The Clans are, afterall, the same ones that when they arrived in the I.S expected the Houses to know what batchall meant, to declare the forces they were defending, and to fight in open, honourable, trials.
For about 200 years the Clans stagnated- the Elemental was created in the 29th Century, and no new suits emerged until after Operation Klondike. Ditto for new weapons such as Heavy Lasers, ATMs and HAGs. Even the Jaguars' Protomechs were only designed out of desperation.
The OP was asking why the Clans didn't have transportation available for their Supernovas. I provided several points why they hadn't needed them before. Do they need them now? Probably.
Doesn't mean the Clans know that. They aren't exactly the...greatest at looking ahead. That includes the Scorpions and Nova Cats.