Dr_Ju_ju

Looks like the problem is at their end, so you'll just have to wait....

If you have a 3D printer, you can find design/ideas on Thingiverse e.g. https://www.thingiverse.com/thing:995503

You could go to 70-80% infill, but what pattern overlaps etc. can also have an impact... 

Have a look at PrusaSlicer (https://www.prusa3d.com/prusaslicer/) Personally, I find it's the best one around at the moment & I even have paid-for slicers e.g. Simplify3D....  

Also what Slicer are you using ??  & the in-fill you used on the print ?

Have look in the APT help file, but for multiple cameras you need to use/configure "Multi-Camera Operation" which means using different start up options..... 

What camera is PHD configured to use in the ZWO\Ascom driver ? it has a switch camera toggle....

For me, for prints that I want to ensure remain in 'shape', I don't use PLA, except for Prusa's Prusament PLA, or better still PETG/ASA/ABS filaments.... 

have a look at FIlaprint (https://shop.3dfilaprint.com/) I find are reasonably priced & fast shipping etc... 

I've had a few of those covers, & I'm sorry to say I wouldn't recommend them long term, as they easily wear-away & leak profusely...

In the end I bought some of this material (https://www.ebay.co.uk/itm/384139905196?hash=item597085c8ac:g:2QsAAOSwF05gkV3s) & knocked up a pair of covers.

Unless you want the added features of the Pro version, what you have is free (you can still make a donation) see https://github.com/marcocipriani01/Telescope.Touch

In "Device Manager", under "Ports (COM & LPT)", if you right click & select properties, what does the HitecAstro show as the manufacturer ?   

I make my own adaptors using either the newer Prolific chipsets or the FTDI chipset, and so load hardware drivers appropriate for those chipsets.  

Even with the older type mount, it's what I have, don't connect via the handset (and putting it into PC direct mode), plug it directly into the port that the handset plugs into....

Honestly, I would still suspect the USB connectivity between the obsy & the PC, especially, as pointed out, if you have recently applied any w$ updates to ver. 20H2 (19042.1110), which have had some some hardware 'fixes'.... 

and what happens when you put the pc in the obsy and run everything locally ?  i.e. don't use the USB extender etc...

FYI, The title says it all, but for those toying with imaging manipulation software, Affinity Photo now allows direct importing of FITS files  (at the bottom https://forum.affinity.serif.com/index.php?/topic/54243-fits-file-format/page/2/&tab=comments#comment-818566)  

I've had one of those linked sharpeners for a number of years, and as Steve says, don't expect to get accurate results, but for quick jobs, especially a quick drill bit honing etc., they are ideal.

For super accuracy, angles & square cutting surfaces etc., I have an oil-stone with accurate jigs, which takes a little longer to use, but for plane blades, which require dual angles, will always produce the best results.

What are you actually cooling ??  the body or the sensor, which ideally is what is required to be cooled ....

correct

have a look at this http://eq-mod.sourceforge.net/

is the hand controller actually in AZ or EQ mode ??

for driving the mount, have a look for EQMod Ascom drivers etc....

Nina doesn't have to use a planetarium software, but its much easier, when you have one around (Stellarium, CDC etc.), as all the software link up with each other as long as you've installed & configured all the relevant drivers etc.... 

and the mount is ??...... is the power supply sufficient & accurate ?  and the motors properly engaging with the gears and there is no sloppiness\binding ?? 

It also pointlessly bumps up the price when you want a new cable.....   

just use a standard Ethernet 1-1 cable, not cross-over, it will work fine....

Being Windows 7, also prompts to the laptop being quite 'old', so I hate to say it, but it may be time to consider some updates....  & they don't have to be too expensive !!

I normally run 3 cameras during a session, 2 ASI (1600M & 120M (both driven through a USB 3 port) & a Canon 600D (USB 2).

The separation into USB2/3 helps, but I also use BackyardEOS to drive the Canon camera(s) (I sometimes also use an 1100D, using an additional instance of BackyardEOS ) & I don't get any problems with USB bus conflicts... 

I take it you're using Microsoft? then, using device manager, check that none of your USB ports are configured with a sleep timeout also in Power Management, check for the same....