What you appear to be asking for is the removal of sustained attack, as by removing the timer, would mean there is no sustained attack,unless you just mean you can carry on attacking the same invader/ghost for as long as it takes to kill it.

From your forum account registration date, I am guessing that you havent been playing the game very long.

The quality of what you get dropping from one item from an invader is much more complicated than being able to rack up your sustained attack level, or being able to hit the target again within the allotted time of one hour.

For example if the target expires before reaching your maximum % sustained attack bonus, then its a waste of hero invader skill points,or if you havent enough sustained attack levels, then you will max out your % bonus before the target expires.

In order to improve the quality of the drop, you need to have, more skill points from higher experience level, and ability to target higher levels of invader/ghost,(see the relevant trees in the oracle) the drawback to this is it costs time or money to get there,and when you do it costs more energy to despatch them.

Though it has improved recently, you will not get very far with any free energy that the game gives you, you have to buy energy,as Ideally you need to be able to finish of your target before someone else does it instead,or its removed as "out of time on the map".

As with all bonuses, though they are worth having, the "hero energy restoration armour"doesnt do very much, and is insignificant if you are buying energy, which as mentioned before , is a must.

For those reliant on free energy, there are ways to increase the basic maximum level of 1000 energy,e.g.gems,town skins,and using hero skill points more efficently.

For the most part ,you will benefit if you concentrate on at best a few of the different invaders rather than casting your net wide.

Whatever your style of play,especially if you are planning on playing long term, you will do well to concentrate on Royal Guardsman.

Firstly thank you for your response, secondly I'm not sure if my post was clear enough; the only thing I think should be removed is the count down timer for the sustained attack.

It serves little use other than stopping free to play or weaker players from maxing out their invader/ghost attacks.

I have maxed invader knowledge and hero points for invaders, legendary invader equipment and gems plus hero restoration armor. 

The rewards you get do get better the more your sustained attack grows, as you take more percentage of health away from invaders ghosts.

What's the point in have up to 600% sustained attack bonus if you can't get the energy to use it, at least if the timer is removed you can make the most of the knowledge and skills we all work hard for.

I can't see a down side to this, it allows weaker players to be more productive farming invaders/Ghosts, gives players more reas on to build and use hero energy restoration armor while still maintaining the need to buy energy to get points from events, and to get loot faster.

Obviously the drop rates on loot have other variables, but how much damage you can do in one shot is one of them, and as I've already said there is no point to the time limit on sustained attack bonus.

If there is a downside please let me know,  as I can only see good things from it, as it benefits everyone.

Thank you for taking the time to respond, I have all the knowledge, skills and hero invader armor/gems, but obviously I get bottle necked with the sustained attack vs the hero energy restoration rate.

Currently at best my restoration with 5/6 hero restoration armor is roughly 520 points an hour, but my point is I don't see much use in the time limit for the hero sustained attack.

Much the opposite, I feel it would help more players to remove this mechanic from the game, as it would still only have limited effect on players spending as you still have to wait for the hero energy to recover. 

But it would give more viability to the hero restoration armor as well have allowing people to compete in game more.

I can't see any negative effect as players will stI'll buy energy packs so they can get invader crafting items faster.