No because SFF's  have a long narrow STICK not a cube shape.

ALL of them these days are SMALLER Than TFX now.

Even the supposed TOWERS are smaller than real towers.

You can put that OUTSIDE the case but you have to modify the wiring as well on most units now.

https://www.moddiy.com/products/Dell-Inspiron-3650-PSU-Main-Power-24-Pin-to-8-Pin-Adapter-Cable-30cm.html

Then it's practically false advertising that it can fit into SFF's.

Its not false advertising.

SFX and TFX are smaller than ATX.

Current Dell power supplies are Smaller than SFX or TFX and use proprietary 6 pin or 8 pin connectors instead of the standard 20 or 24 pin.

WHAT IS SFX-L