Hi, I coded a little online-applet to allow for controlled/determinisitc counterbalancing for pavlovia experiments. That is, it allows you to get exactly as many participants in a between-subjects factor level as you specify, which is helpful if pure randomization is not sufficient (e.g., when having a lot of different groups and a small sample or when having significantly different drop-out rates across the conditions). It’s basically an alternative to the VESPR-Study portal with less functionality but easier and faster to set up. You may try it on my shinyapps.io page. However, since there is a usage time limit for a free account there, which may be exceeded if many people use it, you may want to get it from my github page and upload it to your own shinyapps.io account.
Let me know what you think or if you need help!