the most important is plan for the unplanned, do not rush if the weather sets you back

the mentality is very important, sometimes just need to do a reality check, and don't just tunnel vision into riding towards the destination. Like jaycee1 said, sometimes all u need is a coffee break and the worst weather passes

my rain gear is stupid difficult to attach, the internal liner type.
so it's clear I do not have one suitable for quick on-off for touring purpose. Key is to get the right gear.

I know what you mean, haha... 5 seconds is enough to soak. Taiping is well known for rain.

Back to your question, I did a 600km ride with that rain liner attached, with sprinkles of rain along the way. I think keeping dry as much as possible at the destination was important. Otherwise, I don't mind getting soaked. The rain liner was not comfortable, so I zip down the jacket and that definitely helps. Was it the right choice? Given the circumstance, I think it was the right call.

There are other considerations as well, like, how cold will it get? Will it affect riding comfort and deteriorate the fatigue level?
I can ride 10+ hours a day for short weekend trips on my sports bike, so it's worth knowing how much riding mana I have.

One of the best feeling is riding dry and warm in a heavy rain, and a good quality water flinging visor. It's definitely better than riding all soaking wet, feeling cold and with almost zero vision.

Riding comfort is very important, and water proofing is one key aspects for touring.

Oh, another consideration to stop is other cars, they tend to aquaplane and... u know la.

it takes some riders many years to realize, along the way they have spent too much money on subpar quality equipment, and the best way is to buy the right one at first

helmets, riding jacket, pants, boots, gloves

of course these are not versatile but they overlap, for example it's really troublesome dealing with DD straps at customs.

some spent all 1.5k on the helmet first...

branded CE padding will also break in half, mine one crumbled become powder

What is the name of the app?