I'm reviewing the upgrades I've applied to my TronXY X5SA todate. I've listed and timestamped the upgrades below along with the links to all of the printable items so feel free to pickandchoose what interests you!

00:00 Intro
01:21 Corner Brackets/Reinforcement
02:32 Motor Mount/Pully Alignment Washers
04:56 Print Bed Surface
06:43 Bed Leveling Hats/ZSync Mod
09:25 Direct Drive Carriage + XAxis Linear Rail
15:45 Meanwell PSU and SKR 1.4
19:25 Stallguard Comments
21:34 Marlin/Klipper on TronXY (Chitu) Board
23:27 Conclusions

Upgrade #1: 2020 Corner Brackets
The 2020 brackets I prefer to use are 40mm wide and use 4x m4 washers and Tnuts:
Brackets: https://www.amazon.com/gp/product/B07...
M4 Bolts: https://www.amazon.com/gp/product/B08...
M4 TSlot Nuts: https://www.amazon.com/gp/product/B07...
2040 to 2020 Bracket: https://www.thingiverse.com/thing:485...

Upgrade #2: Motor Mounts and Pully Washers
Motor Mounts and Washers: https://www.thingiverse.com/thing:479...

Upgrade #3: Bed Surface
GizmoDorks PEI Sheet: https://www.amazon.com/GizmoDorksSh...
Check local glass shops for 16" tempered or borosilicate glass at 3/16 thickness

Upgrade #4: Bed Leveling
Bed Leveling/Sync Tension Stepper Hats: https://www.thingiverse.com/thing:485...
ZSync Kit (AZ): https://www.amazon.com/gp/product/B08...
ZSync Kit (Ali): https://www.aliexpress.com/item/10050...
GT2 Pulleys: https://www.amazon.com/gp/product/B07...

Upgrade #5: Linear Rail and Direct Drive Extruder
Liner Rail: https://www.amazon.com/TwotreesSlidi...
UnderMounted DirectDrive Extruder (does not require Xaxis/pillow washers): https://www.thingiverse.com/thing:480...
TopMounted DirectDrive Extruder: https://www.thingiverse.com/thing:485...

Upgrade #6: PSU and Mainboard
Meanwell PSU Mount: https://www.thingiverse.com/thing:485...
SKR 1.4 w/ tmc2209: https://www.amazon.com/BIGTREETECHPr...
Cheap LCD: https://www.amazon.com/BIQUDisplayC...
Cases for SKR, Pi, and LCD: https://www.thingiverse.com/thing:485...

And here are the assorted tools and gadgets you see in the video: https://www.thingiverse.com/thing:485...

For the TronXY Chitu board:
Follow these instructions for installing Marlin: https://github.com/rhapsodyv/Configur...
Follow these instructions for installing Klipper: https://gist.github.com/cab404/b7bcbb...
EXCEPT don't use the embedded update.cbd. Either check the comments for instructions on the make menuconfig and build yourself or use this one:
https://drive.google.com/file/d/1uC90...

For the SKR, there are plenty of instructions for both Marlin and Klipper so I won't repeat them here. I'm printing at 150mm/s at 3000mm/s2 accel for most moves and 1000mm/s2 for outer shell. Klipper's resonance compensation helped a little but I couldn't get anything out of pressure advance or corner smoothing that worked much better than untuned. YMMV.