Haha, thanks, totally missed that.
To the OP, you could get a second small uth for the front on a separate thermostat and run it so the cool end is a little higher. Or if you can, move the uth towards the cool side a bit. Getting a bigger uth may work too to bump up the cool side but make sure it's on a thermostat and the hot spot doesn't get too hot. You might have to try a few things to tweak it.
You can find foam type shelf liner at hardware stores to use as insulation around the outside of the tub. It's not super effective but it helps a bit.