I used a 1mm shim to take up the play on my E5, then just dropped the top collar into place.
That left minimal play in the mainshaft, just enough that the jesus bolt still fits without pressure and the middle and lower main bearings aren't preloaded.
The shim was with my kit when I bought it (pre-loved/almost new) so am not sure of the origin of the shims.
I think it might be part Synergy #109-110, if you decide to go that way.