note: this may be common knowledge, sorry if this is something that everyone knows or something that everyone asks about all the time.   I've noticed that there is a significant difference between the speed of voodoo dolls on conveyor belts between PrBOOM+ and ZDOOM which threw off my timings when I tested them in PRB+. So I made this beauty to test things out:     Here's how it works: the three long sectors are conveyor belts (action 253) with the lenghts of the action lines of 8, 16 and 32 respectively. Trigger lines along the way are opening pillars to the right and they're all 64 units apart. I used a stopwatch to measure how much time passes between pillars to determine time it takes a voodoo doll to cross 64 units.   There are two main scenarios. The first one is the regular time between two pillars 64 units apart. The second one was measuring the time of the initial 64 units. The reason: voodoo dolls are unlocked, in this case, by a door (action 118) and there's a slight delay due to the fact that a door has to open and the voodoo dolls needs to gain speed.   Here's the problem though. It seems that in PRB+ in the case of the first two conveyors, 8 and 16 unit long, the voodoo doll is NOT moving at the proper speed. The player placed on top of one of them is moving significantly slower than the conveyor itself. The issue no longer applies to conveyor lines that are 32 or longer (the break point is 22, that's the shortest line that has the proper speed). Now, if I wiggle a little bit and stop, the speed issue is fixed on those slower conveyors.   Another thing to note: the doors are 8 units thick and are not conveyors themselves. In ZDOOM that makes no difference. In PRB+ the player briefly speeds up on those sectors.   So, here are the rough timings for crossing 64 units:   ACTION 253 / 8 UNITS LONG
ZDOOM: 7,2 sec
PRB+: 7,4 sec
PRB+ broken: 1 min 18sec   ACTION 253 / 16 UNITS LONG
ZDOOM: 3,7 sec
PRB+: 3,6 sec
PRB+ broken: 39 sec   ACTION 253 / 32 UNITS LONG
ZDOOM: 1,8 sec
PRB+: 1,8 sec
ZDOOM: 2,7 sec
PRB+: 2 sec
PRB+ broken: n/a   It would appear that there's close to no difference between ZDOOM and PRB+ after all, unless you're doing some super precise trickery that has to be absolutely perfect. As long as you're using conveyor lines are at least 22 units long that is, according to my masterful experiments.
_________________________ The reason I'm bringing this up is because in my stuff I use voodoo dolls on conveyors to trigger things sequentially but I'm not doing anything that requires perfect precision. So my question is: am I right about this or are there some other details that have to be considered? I googled some old thread where people were suggesting using lowering floors to help with the timing differences between PRB+ and ZDOOM... so I'm not sure. But if all I really need to do is to make sure the conveyor lines are long enough and that will guarantee roughly the same results, I will try to keep the PRB+ support.   BONUS QUESTIONS
While I'm at it, I might as well ask some things related to PRB+. I'm using what I believe is the last official version,   1. It would appear that when I try to use GLBOOM+, voodoo dolls do not appear at all. They spawn just fine in software. This is true for all maps that use voodoo dolls. I'm not sure what's going on here. I re-downloaded PRB+ and the issue persists. [EDIT: SOLVED]   2. Since I know nothing about how compatibilities work in PRB+, let me ask this. To make sure sure the right compatibilities are set for strong limit removing format that only uses BOOM features (let's say Vela Pax or Deus Vult II), all I need is to make a shortcut of prboom-plus.exe and add complevel so it looks like this in properties, is that correct?   prboom-plus.exe" -complevel 9   3. Also, is complevel in any way related to compatibility settings in PRB+ itself? I mean, from what I understand it is but there's a whole section called DOOM Compatibility in the menu but it doesn't seem to be affected by using complevel at all.