OK, thanks again.
I ran into issues at once as I tried to download the UpgradeMODX extra. The usual provider was gone and I was unable to add it.
I then read your article and it was spot on for me. (Wish I've found it yesterday
I was missing all the fields you list except 'modx_context.name'.
I've added them now and also fixed the type on the 'modx_users.createdon' field.
I've installed the extra which hopefully wil take care of future updates.
Excellent guide, btw!