I'm not sure what you mean by "Each subsequent tournament result then multiplies the player's rating by zero"?
My understanding was that if you dropped below 1400 and were no longer on the rated list then you would be treated as an unrated player - so at the end of each month, they look at all the rated games you have played in consecutive months over up to around the past two years, calculate a fractional score (points scored including two fictional draws / number of games including the two draws) to calculate a rating offset, and apply that offset to the average of your opponents' ratings (including two fictional 1800s), to calculate a new rating - and if this is above 1400, then you once again have a published rating.
The development coefficient shouldn't be taken into account until you're back on the rating list through the "new player" mechanism.
Previously, after a poor tournament result, my FIDE rapid rating dropped below 1400, and I was again an unrated player. The problem is that FIDE doesn't just reset the rating in this case, but also the development coefficient. Each subsequent tournament result then multiplies the player's rating by zero. Although I subsequently played several official tournaments in a row with a significantly higher rating than 1400, my FIDE RAPID ELO remains at 0. Have you encountered this problem? The national chess federation informed me that this problem with FIDE has been ongoing for many months.