Practical rules of thumb for long-run LED strip installs?

I’m working on a few LED strip installs where the runs are long enough that the “usual beginner advice” (just pick a PSU and stick the strip up) stops working.

Typical scenarios:

24V constant-voltage strips for indirect/cove lighting, ~5–20m per run

Sometimes addressable strips (SPI-style) where data integrity becomes a factor

Indoor installs in aluminum channels / diffusers (so heat and wiring neatness matter)

I’d love to collect practical rules of thumb from people who’ve done this at scale. In particular:

Power injection

What’s your “inject every X meters” heuristic for 12V vs 24V?

Do you prefer single-end + injections, or powering both ends (and why)?

Any go-to wire gauge guidance for common power levels (say 50–200W per run)?

Fusing & safety

Do you fuse each injection branch? Inline blade fuses? Something else?

Any wiring patterns you’ve found safer/cleaner for hidden runs?

Addressable / data integrity

When do you stop trusting a single data line and switch to differential / RS-485 style transport?

Do you routinely add a series resistor on data, and if so what values actually help in the field?

Any best practices for grounding when the strip and controller are far apart?

Heat & longevity

For strips in channels with diffusers: any “keep it under X W/m” guidance to avoid long-term yellowing / adhesive failure?

If you have favorite references (calculators, wiring diagrams, field-tested guidelines), I’d appreciate links. I’m not looking to sell anything—just trying to avoid the common failure modes (dim tail, flicker, random glitches) and build a repeatable checklist.