I ended up purchasing the following socket and adapter for all my GE jobs (picture in attachment).
Socket is 3/4 drive and deep enough for any shaft legth, hence the adapter.
Correct size would have been 1-5/8 but it's really tight if there are soap/mineral deposits, so 43mm is only slightly larger. Pays for itself in 2 jobs or less in letting you schedule 1 more customer visit that day and much less money in the swear jar
Was using the spanner and just holding the tub while hammering it, but for 10 years old GE with the aluminium hub, I had a few where the tub broke free before the nut came loose.
The Supco TB123A does the same job and is cheaper than GE OEM. Trick is to wrap the tub nut in electrical tape until the adapter fits tightly so you don't have to hold anything while smashing it... but if the hub breaks and you can no longer hold the tub, the transmission ends up getting all the knocks...
This is why I'll go the impact way for all GEs, but not for Samsungs yet as they still require service within 2 years