Few weeks ago I tried to compute the Roobet house edge and I found 4%.
A 100 is a small number to find the exact house edge. I have not gone through any experimentation but the site used to claim that they are providing 1% house edge and on last Christmas, they admitted to increase their house edge to 2% (average). As they say "RTP is now ~ 98% on average, across all games modes" in this post from December 2019 https://www.twitlonger.com/show/n_1sr3buq
I could not find any other reference about their housed edge which is a put down for me.
So when you say average 3% on house games. Crash could be having nearly 4% house edge as the Dice game in Roobet has an edge of 2.5%.