while assembling my Openrov I had to make some modifications: First one is a different endcap-design for the battery tubes. The acrylic parts for the endcaps were missing in my kit, so I decided to make new ones from plastic. Since my lathe was aleady running I also made some brackets for fixing the tubes. I was afread, that the strongs springs would reopen the tube, therefore I decided to make a version that could be screwed. I copied the orignal design for the o-rings but added a groove to put a second one that is sqeezed by srewing the endcap on. I Hope the pictures explain what I mean.
The other modification is concerning the tether. I purchased a cheap extension cord, took out the plugs and the cable an put the tether on the coil. The connection with the topside-adapter is made with a plug that rotates free. This whole setup is very compact and handy. again, see the pictures.
best regards from Switzeland.