How would that work? Why would a hacker ever enable those features on his local hardware?
Thinking in-universe here, where this sort of system exists, wearing an equivalent of a full-dive-condom which prevents the feedback you speak of, would maybe make an operator too slow in responding to countermeasures or make the whole process the mental equivalent of walking through treacle. A skilled operator is more effective without it, despite the higher risk?
All of the above is pretty moot though in the real world, computers can and always will operate at a million times the speed of a person, I can't really see the value proposition of being "in" the computer, when all you'd ever really be doing is deploying icebreakers out ahead of you and waiting for the response
Galvanic isolation of high-speed digital electronics today is already fairly difficult. Imagine adding optical isolaton all the data ports on desktop computers, including the high-speed ones like 20 Gbps USB or Thunderbolt, it's entirely possible but difficult and expensive, sometimes with compatibility issues. USB 2.0 High Speed is a notorious example, it's difficult to isolate (until it was recently solved by some new ASICs from TI and Analog Devices) not because of any inherent technical problems of data transmission, but because its signaling and protocol are not designed with transparent repeaters in mind. Thus, galvanic isolation is only used in highly specialized applications. As a result, a USB Killer can easily destroy most PCs because the signal is often wired straightly into the CPU (SoC).
One can only imagine the difficulties of doing the same for a neurosynaptic link in a Sci-Fi world. For example, in Ghost in the Shell, ICE is in widespread use, meanwhile isolating firewalls do exist but they're rare, mainly used by intelligence agencies. They are also disposable devices and would be completely destroyed after an electrical overstress (not unlike real-world galvanic isolation...) Further, one can use bandwidth limitation to rationalize the "the mental equivalent of walking through treacle" part of your plot.
Of course, as you've pointed out, as computers operate much faster than the human time-scale, the argument of bandwidth is not really that convincing.
Calculators!
We have over time abstracted away the hard-for-people-easy-for-computers tasks to the point often people just do the hard-for-computers stuff, like interpretation of results, and coordination of next steps
A more contemporary example might be something like headphones: as far as I know, limits on sound output are software-based, not hardware. Theoretically a hacker could modify these software limits and output extremely loud sounds.
> Gadgets can be hacked to produce 'dangerous' sounds, says researcher https://www.bbc.com/news/technology-49291665
Seems pretty much impossible.
True, my headphones could be modified for it. In fact I once looked into the firmware of a previous model, and apparently there was 16MB RAM, 2 cores, and sqlite in there. The darn thing could run DOOM if there was a display attached.
But an application doesn't get to talk Bluetooth to my headphones, it only gets to submit audio.
Besides that, audio is logarithmic. If the internal amplifier can produce 2X of the software limit, that only adds 3db. Maybe annoying, but nowhere near bad enough to do serious harm.