@Kent1Cooper wrote:
....
.... the bounding box of Mtext "reaches" leftward to encompass leading spaces if present.... So:
1. divide up the Mtext's content at the spaces, keeping each space as part of the string of the following word;
....
3. put in individual Mtext objects for each word, individually set to zero defined width, positioning them by their bounding boxes which [after the first] will include the spacing from the previous one;
....
I decided to try that approach [adding to that description the forcing of no columns in Mtext because you can't give it zero width otherwise, and the removal of the leading spaces in each word after its position is established], just as an interesting exercise. And I expanded to accept selection of plain Text. The result is the attached -- see the comments at the top of the file.
But I found the include-the-leading-spaces bounding boxes must be a little short of actually reflecting the width of the leading spaces, because I got this kind of result:

The green is the original, and the magenta the result of applying the MTBM command to a copy-in-place of it. [I moved the green original in front with DRAWORDER to get out from behind the result's masking, so the comparison is apparent.] The first word is exactly under the original, but the spacing between the rest tightens in a little as they go.
I decided to try @ВeekeeCZ 's accepted-solution MaskWords command at Message 28, to see whether it does better at that. I found that it has better [though not perfect] relative positioning between the separate words overall, but in this case the results are shifted out of place, in both directions:

In some further trials, I found that didn't happen if the source object was at zero rotation, so I wondered whether the issue is rotation-angle-dependent, and sure enough.... Here, the green are the originals and the red are the results of MaskWords applied to a red copy exactly in place [I did not Move the results -- this is where they landed]:

Not only does the position shift get worse with increasing difference from 0° of the rotation angle, but note the irregular spacing in both the 90° and 270° examples [the "a" and "test" are too close together], which for some reason doesn't happen in the 180° example.
My MTBM command still has the same slight shortening of the spacing between words at other rotation angles, but the angle difference has no effect:

Those are from Mtext originals. From a plain-Text original at 90°, MaskWords had the positional shift and a worse spacing reduction problem; MTBM handles it the same as an Mtext original:

I haven't studied MaskWords in detail to try to figure out what could be causing these shifts and spacing issues with source objects at rotations other than 0° -- I leave that to @ВeekeeCZ to investigate. I will also investigate MTBM's spacing-tightening issue, to see whether there's a way to get the results more exactly positioned in relation to the source objects.
Kent Cooper, AIA