Phin77: Here's my experience with this problem, hopefully it will be of use to others. This post necessarily will contain spoilers about the boss fight and its attack pattern.
TLDR: Rush whatever platform the boss is currently preparing to unleash its attack on.
For me, this prevented the gun-toting hiss from spawning on said platform. THEY are the cause of the crash (for my system at least). The clock spewing attack that the anchor is unleashes is just correlation.. not causation. So long as you stand to the side of the platform, it's attacks will mostly miss you and you can dart ahead to its next attack location. It attacks in a clockwise pattern (appropriately) so get ahead of it. Once it opens up to attack use launch to chuck anything (mostly likely a clock) into the glowing orb in its maw. If you time it right, this will negate its attack, which while not the reason for the game crashing, will at least keep you safe. It will spawn in kamikaze hiss that fly towards you to blow up.. These are fine.. They didn't crash the game for me.. Only the gunner hiss do. If you are keeping just ahead of the anchor, being on the platform it's prepping to attack, these will not spawn.
I ran the game at the full nVidia optimized settings for my card and the clock attack goes off without a hitch if you can keep the gunner hiss from spawning in.
I tried all the recommended fixes on gog's/steam's forums and nothing worked. This includes: lowering all graphical settings to their lowest/disabled values with a resolution of 640x480 and turning in-game volume all the way down(?), turning off full screen optimization in the executable's compatibility settings, forcing physX to CPU mode only. There was one about swapping dll files around.. Nothing worked.
I have reported my experience to Remedy/505.
CPU: Intel i7-6700K @ 4.0 Ghz
RAM: 32GB DDR4 GSkill Ripjaw series
GPU: nVidia GTX 970 FTW2 (4GB video ram)
OS: Windows 10 Pro (up to date with as much telemetry disabled as possible ;)
Edited: fixed typo
I have the same setup as you, except that I'm running a 2060 Super. I had to rush through the battle as quickly as possible, using explosives and dash-gliding.