I have a 15Khz arcade monitor and AVGA card.
When I used Stuzza'a version of Mekaw it wouldent go full screen which was a pain , instead flashing back to the GUI with the game in a wee box in the corner.
Finally figured out how to fix it so it boots into full screen flicker free .
You need to edit the Meka.blt file and change the default resolutions to either 321x240 or 256x240 (these are AVGA resolutions for the video card)
For my setup it was the [Smooth : win] section.
Voila!!! flicker free game play just like GensFE.