Nope, twice is too many times… not buying those type heaters again…

[Sleeveless]

The warning should probably not be ignored as if the unit gets too hot it will burn out faster. The key isn't angle but as you mentioned current flowing over the unit.

I ignored it at the up/down vertical since the heat comes from the bottom of the tube, rises and hits the sensor at the top causing a 30 second to 1 minute raise from 78 to a max of 80, then immediately hits 78 again. All other area's of the tank remained 78 as I have multiple thermometers just to keep my ocd in check. And the LF warning on that is really a feel good option in my opinion, especially after the seeing Fluval mention it doesn't impact any functionality.