I'm reviewing the upgrades I've applied to my TronXY X5SA to-date. I've listed and timestamped the upgrades below along with the links to all of the printable items so feel free to pick-and-choose 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/Z-Sync Mod
09:25 Direct Drive Carriage + X-Axis 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 T-nuts:
Brackets: https://www.amazon.com/gp/product/B07...
M4 Bolts: https://www.amazon.com/gp/product/B08...
M4 T-Slot 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/Gizmo-Dorks-Sh...
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...
Z-Sync Kit (AZ): https://www.amazon.com/gp/product/B08...
Z-Sync Kit (Ali): https://www.aliexpress.com/item/10050...
GT-2 Pulleys: https://www.amazon.com/gp/product/B07...

Upgrade #5: Linear Rail and Direct Drive Extruder
Liner Rail: https://www.amazon.com/Twotrees-Slidi...
Under-Mounted Direct-Drive Extruder (does not require X-axis/pillow washers): https://www.thingiverse.com/thing:480...
Top-Mounted Direct-Drive 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/BIGTREETECH-Pr...
Cheap LCD: https://www.amazon.com/BIQU-Display-C...
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 un-tuned. YMMV.