A different experience with 1.53.
I am running 1.53 and have not seen the loss of scenes using a Restart. I had scenes from 1.51 and 1.52 which were carried forward into 1.53. Also scenes created on 1.53 remain after a Restart on my system.
The unit number did not auto sequence on 1.51 or 1.52. I noted this in a post back in June. Would be a nice idea for scenes where EZSrve is the controller. Might be a problem for things like a KPL where someone is trying to add additional devices to the given button number.
I cannot add a scene with unit number 00. Leaving the unit field blank or setting it to 0 or 00 results in a popup indicating unit number is needed or a valid unit number is needed before a Controller can be added to the Scene.