Is there a workaround for the 4h30m Lapz working time limit?

Yes, there is.

LapZ clock limit is 6 hexadecimal digits (FFFFFF milliseconds), this is 16777215 ms = 4:39:37.215

ZRound can run longer races if it is configured properly (see LapZ configuration page). You must uncheck the “Use LapZ clock” . This will allow the PC system clock to be used so the LapZ time limit will be avoided. You can see there is a warning about use this option ONLY for race time less tan 4h39m.

You need also to reset the LapZ bridge before every 4:39. If this is not done the lapz will stop counting. This can be done manually by using the “Reset Bridge” button or automatically if you check the “Autoreset LapZ Bridge”. If you check the “autoreset”, it will be done every X minutes, where X is the value configured into the “Minutes to bridge reset alarm”. If a car goes under the LapZ bridge just when reset is done it won’t be counted (reset time is less than 2 seconds). FYI, I used the “autoreset mode” in the 24h race and all laps were counted but if you want to grant 0% lap missed you must use the “manual” mode. I think a missed lap won’t decide such a long race and the auto mode should be good enough.