I've thought about this and if the Sovereign is at risk of being discontinued. I think not, because every company out there has "less complicated" units in their line up to sell to people who don't like the computer age in terms of being loaded down with tons of bells and whistles. With them discontinuing the Musketeer in the US that doesn't leave any non-computer display models left, besides the Sovereign.
For an upgrade it doesn't even have to be electronics in any fashion. Same box, just put a lighter shaft, hand grip, arm cup, and battery in it. Make it so the meter can mount on top of the grip, or at least in it's same location on the shaft that it currently mounts but throw a 50 cent piece of plastic in the box to raise it above the grip to see easier.
As for batteries, how about a lithium Ion battery to cut down the weight, or at least 10 AAA nimh cells in 1000ma capacity to match the old Sub A pack yet be much lighter. With those the current wall "charger" they supply with it will work just fine.
The only electrical modification I'd like to see would be a simple jack installed on the back of the box for a remote PP. They could even sell the remote PP switch as an extra and make it so it easily mounts on the hand grip. Better yet, sell it already installed in a new hand grip so it's as cleaned up in looks and easy to put on the machine in place of the old grip.
Of course that pig of a heavy arm cup should be replaced. 8.8oz is rediculous in terms of how heavy it is.
Throw a version of the Pro Coil on it or contract with Detech to put the 12x10 on it.
Like you said, installing the rubber boot switches at the factory would also help sales.
All the above things would be minor hardware improvements that wouldn't really amount to any more production costs. Very little if any, yet it would make the machine so much lighter and user friendly. Call it a Sovereign XL, standing for Extra Light.
If they were to do anything with the electronics then I like the idea others have had about making Iron Mask adjustable. Keep the regular on/off Iron mask switch, and all the other switches as they are as well. Just change the discrimination dial to where if it drops below a marked line then you are lowering Iron Mask as you go lower, to the point where when it's all the way down it's at zero iron discrimination. Rise it above that scale and it clicks back into normal discrimination with the normal existing range. Nobody who would want to lower or zero out iron discrimination at a site is going to want any other form of discrimination anyway, so I don't see a point in making these seperate controls where you can run some discrimination yet accept iron. Makes perfect logical sense to me to do it that way. You'd still have the normal on/off Iron Mask, which means of course how hard the unit tries to pull a good target out of an iron signal, so this function is still intact, it's just that now you can click the discrimination dial below iron elimination and lower it all the way to total acceptance if you want.
As for the notch, I would like to see an adjustable window range, meaning how wide it is. Make it so you can narrow it down as tiny as to just knock out one specific number, or go so wide that it's roughly double the current width, though it's current 12.5 digit width on my machine is just about perfect for killing pulling tabs. Minelab must have put some thought into that. Also, you'd still have the regular control for notch to move it up and down the scale to position it. So far we haven't had to add more switches or anything like that to the face plate with the above other features, and this can still be true with the notch. They have POT dials that have the main (current notch control) in it's normal place, yet with a smaller pot control on top of that dial to adjust notch width. See how easy that is. No changes to the stock face plate. Even the mod for the discrimination dial doesn't involve new switches, dials, or relocation of things.
The coil cables don't need to be that long. Provide an extension in the box for those who want to hip or chest mount. It's connector would still be well above the water level for people who wade waste deep water hunting, or just throw a water proof connector in the box to use for that.
Finally, a meter should come with the unit that can be thrown on or taken off for water hunting and such just like it is used now. There is no reason for the current meter to cost that much since it's just a basic volt meter and probably costs about $5 or $10 to make. If you aren't going to supply the meter with the unit then at least make it $40 or so. No call for that. Install a back light on the existing meter, which should be real cheap and easy to do on LCD screens and shouldn't even really cost anything in production.
Those are the features I'd like to see. Most of them would cost nothing or pennies to make. In fact, just eliminating the extra aluminum in the overly heavy upper shaft would probably save them more money than all these changes would cost.
Come on Minelab! You can save yourself money or add very little to the cost while not really having to do much at all in any changes to the internal electronics. I bet the perspective buyers for the machine would double. Women, people who don't like heavier machines, those who want the Iron Mask control or remote PP, etc.