Low risk, flexible, portable and quick to use bike locks?

[Time Waster]

I'm looking for some kind of deterrent lock for a few uses. One to lock a bike to a rack, two to lock a saddle to the frame. Perhaps both can be done by the same lock, currently using a cable lock to do that and it's ok but looking for better. Security risk is not high, pretty low really.

I like the Abuse folding locks or the newbie foldylocks but they're too pricey. I saw a rockbros version, are they ok for a low risk use?

That option would only suit fixing the bike to the rack. I'd then need something for the saddle. Perhaps a cable tie lock such as hiplock and others do.

Anyone got recommendations? It's it possible to get one lock for it all?

One last thing, I'd like to have a solution that can be fitted to a bike and forgotten about until
needed. The folding locks are great for that. The saddle security I can't figure a good option for. It's a folding bike so the saddle seatpost drops, a cable tie lock could link into a main lock. Or is there a light and very packable cable option that would use the main lock to secure it? Like those d locks plus cables with loops on the ends but lighter.

 

[andrew_s]

For the saddle to the frame lock, I use a Hexlock
It's an update of the old trick of supergluing a ball bearing into the end of an allen bolt, but can be quickly and simply removed using a small key.
They also sell parts such as seatpost bolts that have rounded or conical ends so you can't readily use vice grips.
A limitation is that the allen bolts you are blocking have to be magnetic steel, which some varieties of stainless aren't, so you may have to change the seatpost clamp bolt.

There are also bulkier alternatives such as Pitlock