If the hub is on the vertical there is absolutely no valid reason WHY you cannot do a caulked joint.
When I taught apprentices how to do a caulked joint on the horizontal using lead and oakum and runner it took them a WHOLE 7 minutes to learn to do it.
A Vertical joint takes about 4 minutes to MASTER.
Ty seal is GREAT if your hub is New and If you know if your cast Iron Hub is standard weight Or extra heavy.
If you really want to get in get out without going through the trouble of trying to learn something new do the following
Rent or Borrow a Rigid snap cutter RATCHET type
Cut off the cast Iron pipe just below the hub Or if you have the room You can use a few steel or carbide saw blades with a recip saw and again cut off the hub.
Get a MISSION or No HUB coupling NEVER EVER a Fernco and then you can do this job in any materials your little heart desires and even mix CI and plastic
If you think you may have trouble handling molten lead ask any fishing buddies you may have how they make sinkers?
Im an E mail away if you want to do a caulked joint.