Question: How to make an inert one or an inert multiplication symbol that is invisible?

This is about avoiding that automatic simplifcation removes a factor of "1" before a unit.

Example output with removed factors:

Readers of technical notes not familar with Maple interprete the above missing values before units as layout errors.
Also reading it (e.g. with a screen reader) sounds strange: "m_l equals kg" or "m_1 of kg".  As a work around a float one (i.e.: 1.) can be used, which in some instances does not look as nice as

To improve the above I thought of an inert "1" or an inert multiplication that could be removed by the value command in subsequent calculations (not necessarily visible in a document to the reader when the input is hidden).
I could not find a way for an inert "1". With inert multiplication using %* a grey asterix is printed

Can we make the grey multiplication symbol invisble?

Related discussion on 0 mm and 1 mm

https://www.mapleprimes.com/questions/241946-Round-With-Units#answer313597