It seems that .style is not properly supported (fonts are ignoring may style elements) while the clone command does not allow me to change/alter the actual text.
I have many text elements in my drawing and I don't want the style information repeated for each one of them.
An example svg document would be best if there is one.

If you have clones, <use> elements. It is the svg element which is cloned. You cannot alter basic svg element part of the clone ( otherwise it would not be a clone ).

With svg, the css presentation attributes you can use are https://developer.mozilla.org/en-US/docs/Web/SVG/Attribute/Presentation

Generally speaking, if you are dealing with large numbers of object - do they all need to be displayed at the same time.

Perhaps it may be better to generate and destroy them on demand.

The only way I can think is to do something clever with inheritance on group.

Or use classes on basic text elements