I’m currently flying said 172 from KOPF to KEYW as we type and can confirm that GHPS doesn’t even have a VS button on it.
Clicking the up/down does not show any VS on the LCD either.
Just have to keep count of your clicks on the Bravo dial. If you hover your mouse over the arrow after increasing with the Bravo it will then tell you in tooltip what you’re set to.
There is an “arm” button for the VS though so you could set your altitude click arm. Then click the up arrow or down however it seems to go in 1,000FPM intervals (according to Vertical Speed indicator) but still doesn’t show you on the screen.