My informal tips to dine at Thean Chun, Ipoh.

Many blogs were written about this and I'm not going to repeat with introduction. I would assumed you have a little knowledge about this tourist honeypot. If not, just Google search for "Thean Chun Restaurant", plenty of well written articles and blogs available.

This restaurant is famous for two things : Chicken prawn 'keuh teow' noodles & pork satay.

Tip 1 : Visit for breakfast on a non-school holiday week days. I think they start around 10am.
Pros : Avoid crowd, shorter wait time.
Cons : The soup close to plain, not tasty at all.

Tip 2 : Visit between 3:00pm to 4:00pm on a week day, near to closing time.
Pros : The soup is amazing and with tired hands tend to add more of those special oil.
Cons : Cannot guarantee they still remain open by then. If he allocates less raw material for the day, shop may close earlier.

The Sifu.

If you are unable to follow tip #1 or #2, there is no other choice but to join the merry crowd. The following tips may be helpful for this type of situation.

Tip 3 : Go alone or split up and visitation timing try to follow tip #2
Pros : You get a seat quicker and maybe get to know other enthusiastic travelers like you.
Cons : Waiting time is still quite excruciatingly long and you'll split up with your friends.

Can't wait and unable to follow tip #1, #2 and #3?
Tip 4 : Eat satay instead.
Pros : Wait time short.
Cons : Satay man has higher frequency of absent at work compare to Mr. Tricycle Chicken Prawn noodle 'sifu'. Pork satay is not for everyone.

If all fails to your expectation.
Tip 5 : Go to lesser known places like Loke Wooi Kee or Sin Hoong Fatt (Canning Garden).
Try to visit near to closing time for the best experience.
Ref: https://www.chowhound.com/post/ipoh-malaysia-kai-hor-fun-face-loke-wooi-kee-thean-chun-1013087
Ref: https://chingchailah.blogspot.com/2017/04/kai-si-hor-fun-at-little-katong-canning.html

good luck.