Basically there are 2 types of T8 LED Tube in the market:
1) Single Ended
2) Double Ended

All Philips/LEDVANCE (OSRAM)/GE/OPPLE (1 of the series) are single ended.
Most if not all China branded LED Tubes are double ended.
Both requires slightly different wiring.

Getting LEDs, do not refer the Power Ratings (W). Focus on the lumens output instead.
Eg Philips ECOFit comes in 2 different package. Using 4' as as example:

1) Standard Output- 18W = 1,800 lumen
2) High Output- 20W = 2,100 lumen

There are some more higher end models under the Master series:

1) Standard Output- 10.5W = 1,600 lumen
2) High Output- 14W = 2,100 lumen

The Master series are rated for 50K Hrs lifespan.

You can see how the connection are made to the tube. Double ended T8 LED tubes have L and N on opposite ends.

China 30W? What is the lumen output?
If not sufficient why not go for those 2x fittings?

Most if not all China rated lumen output drops significantly after 1-2 months of use. Just visit any Mr. DIY shops and you will know what I mean.

I will take their specifications with a pinch of salt.
If you have a lux meter only you can tell whether it is degraded (less lumen output) over time.

Your choice, I will always stay clear of these "overclaimed" specifications and stick with reputable brands.

Reputable brands like Philips/LEDVANCE(OSRAM)/GE have at least 2 if not 3 ranges:

1. Consumer (10-15KHrs)
2. Retail/Commercial (20-30KHrs)
3. Professional (>50KHrs)

Only specialize shops can you find option 2 and 3. All shops you can find option 1 (which is fine for most application).
For me my own home, I always go for option 2 or 3 series and skip as much as possible option 1 as I am very lazy to change the tubes/bulbs and I intend to stay in my house long term.
Rule of thumb for most residential we use a 6Hrs utilization per day.
Hence Philips ECOFit (15KHrs) is supposed to last about 7yrs.

Reputable brands follow a L70B50 specifications, meaning to say even an ECOFit is rated 15KHrs, the lumen output cannot drop more than 30% of the rated output. Otherwise it is considered to be "faulty" even though the entire tube is lit up.

Try asking China brand for L70B50 specs!

Yes, using lumen/W is a more accurate measurement of any LED light.
Latest model of Philips Master series only requires 12.5W to produce 2,100 lumen (168 lm/W).
Even the recently soon to be phased out 14W is rated 150lm/W.

As long as the ambient temperature is lower. the lifespan of any LED is longer.
Anyhow, Philips LED are rated for their system lifespan. Some brands quote 50KHrs but is actually the LED chip lifespan and not system (with driver/Power supply).

Philips Master usually around RM 50++. I have been using them since the days it was 16W, then upgrade to 14W and now 12.5W. All also 2,100lm for 4' model.
Problem is my 16W not spoiled yet after 6 years in use.

It is the other way round.
China Tubes = Double Sided
Philips/OSRAM/GE = Single Sided

Single sided tubes can also be reversed if the wiring is done right.

Short answer, NO.
If you are a bit more DIY person, YES. Just need to add 1 wire to the double ended casing.

OIC. Usually in my line the single or double sided are referred to the T8 tubes itself and not the casing.