1. Not really needed, but can be an option: Insert 0.1x10mm Shim on each side of the diff/spool. 2×2 pcs. = 4 pcs. are needed in total. Without the shims the car will still run ok – its just to prevent the diff/spool moving a bit too much sideways.
2. When using Alu Screws, pre-cut threads in the knuckles with steel screw (or M3 forming tap).
3. Take extreme level of care reaching the 13.3mm on step 28 and 32, otherwise you will be not able to reach proper camber settings. 
4. Take care of the direction of inserting the drive shafts (tuning direction of the C-Clips on the driveshafts). This was mentioned on TRF models before, but not with this one anymore.
5. When running elevated lower suspension arms (= higher rollcenter to reach anti dive / anti squat) you can put up to 1mm spacers underneath the rear stabi holders. On front you cannot lift them, as they will interfere with the steering. In this case, leave the stabi links a bit longer than the manual says.
6. When not keen on grinding 54921 blades, use the ones from 11/2021 instead. They fit with some play (as known from TRF420 before)
7. As front axle body lifting support (front outer suspension arm) you can use M3x14mm Buttonhead Screw. The height can be adjusted to your needs. 
8. Take note, that the gear chart has dramatically changed over TRF420: Max. pinion gear size = 43T/64dp, min spur gear is 90T/64dp

My personally used Hop-Up parts:

1. Front & Rear Springs: Axon ST-HL-013 (HLS 2.7 Red) – my favourite on asphalt!
2. Square STM-90 S-Flex Alu and Ti Screw Set (sakaguchinetshop edition with high flex screws for more forgivingness)
3. Axon GS-T6B-111 Spur Gear with Arrowmax AM-364028 Pinion Gear
4. Square SGE-80TB Servohorn (for Futaba 25T)
5. 42118 3x32mm Ti Turnbuckles Blue on rear toe links (more durable)
6. 42120 3x42mm Ti Turnbuckles Blue on front tie rods (more durable)
7. 2x 13404136 TRF420X Carbon Batttery Holder Plates

Electrics: