This is not an issue I have frequent problems with but your post prompted me to check what is going on and what is to be found.
The support.microsoft.com site has a few articles related to the loss of trailing zeros when importing to Access from Excel. So it seems this is a known regular event. You don;t need to be using a monetary format.
Seems to be to do with the import of numerics which as provided as 'text' where the import infers a numeric value is being provided but is unable to to see the data in the characters as the original format is not provided - just the numbers and the decimal place.
The solution offered seems to be in line with what you are currently doing or, if updating pragramatically, they provide code suggestions about suitable approaches.
I think the problem is overcome if you are exporting to a pre-defined database. Only if the export/import is initiated by the application feeding Access is there a problem - or at least that is the way I understand it.
No doubt our resident Access experts can provide chapter and verse on this.
Sorry it's not better news.