You can always use the mechanical VDO senders that we used for years. They read zero when they are at zero. At least the first time you use them. Eventually, with all the shaking, baking, and what have you, they eventually read whatever they feel like

Also, they're not all that accurate, especially at low pressures. They can give you a false sense of security.
We upgraded to the Kavlicos because they are more reliable, but yes, without hardware changes in the D100 series products, they read a bit off zero when at zero. We don't know of any affordable, reliable sender that won't have this issue. This issue doesn't exist on SkyView since it was designed with the senders in mind.
The reality is that your fuel pressure should be >20PSI. If it reads 4 are you going to do anything different than when it reads 0? You're going to keep flying, hope the engine is still running and land ASAP. It's so far out of bounds that it isn't an issue. Kind of like the fact that if your pressure gets up to 56 PSI we'll only say 50 PSI since the sender maxes out.
Seriously, if you prefer an older style mechanical sender, then we can send you one of those back instead.