Planting fruit trees in Thailand?

Eh, if I needed young Thai fruit trees, I would just buy them here in the village. There are 4 growers here for young plantings.
Furthermore, I always come across many sales stalls along the 11.
But we already have the following species on the family grounds.

For coconut palms (3 species), date palms, bananas (6 species), longon (3 species), durian, mangosteen, mango (4 species), papaya, pineapple, rambutan, guava, lime (2 species) and lemon, all I need is the backyard, the front yard, or some locations further away.
You will find them everywhere in a village. Also in Phayao I think.

We do not have oranges, mandarins, etc. Peaches would still work, but we don't like that.

We also have NO European fruit trees in Uttaradit. Apples, pears, plums. Is it too hot for this.
I don't know if it is possible directly in Phayao where you live. Depends on height. Apples, Pears, Cherries, Plums etc.
These trees drop their leaves in the winter, so they need 4 seasons. For a Thai, a tree without leaves often means that it is dead. So it is cut down and processed into firewood. If he ever grows taller than a meter.

It is also not as easy as it seems to grow apples, pears, etc. If you start with 1 kernel or seed, you will be 5 years further before the tree can bear fruit at all.
That's not the only problem. What is important for many European fruit trees is that they must first be grafted. (means to apply a good shoot to the rootstock. The second aspect is that the blossom must be pollinated by one and often another tree. Unless you put several species on the same rootstock. Then it CAN become self-pollinating.
Otherwise you need pollinators. Butterflies, Bees or other insects.
I know that apples, pears and plums grow in certain areas in Chiang Mai and Chaing Rai. But to start it yourself?
To get really fruit bearing trees is a tricky one. Which is an option to bring grafted rootstocks from the Netherlands. These are 30 cm in size. Wrapped in wet newspapers and plastic, they will survive the journey. Whether they get through customs is another.

I know a tree center near Diepenbeek (Hasselt) where they grow old varieties and try to keep them on the market. If you are interested I can try to find out the address. I think it is an activity of the Hogeschool Diepenbeek.

There is also plenty to find on the internet about growing and grafting fruit trees and also which species might or might not flourish in your area.

Rori or other readers,
What are the import restrictions in Thailand for Fruit trees and plants/shrubs?
Want to take some spindle trees and berry bushes in my suitcase.
What is the risk I run if I do this?
Please your response if you are familiar with this matter (import regulations)
Thanks for the effort.
sep Daniel.

first of all I would not introduce any plants or seed because you can cause diseases and pests.
in the us it is strictly forbidden to even import cheese!
first take a look at what grows on your property and examine the soil fertility, and only then go to a garden center to see some DIFFERENT types of large and small fruit to see if they are suitable for your situation.
even better is to do an introductory permaculture course online or take a look at the various thai facebook groups that are already about this.
just doing something like that quickly leads to disappointments that are not necessary and, moreover, exotic plantings are not exactly easy.
with a correct planting plan you can contribute to making the environment where you live more sustainable, because Thailand is lagging behind in this area!