I have 3 ways to check this, but you need to create 3 different accounts, one American, another European and finally Japanese in the first 2 ways.
The first way is that if the game has a trial version, try to download it at the same time from all stores. The result will depend on how many times the trial version has been downloaded. If the trial version is downloaded once it is a global game, if the trial version is downloaded twice it is most likely a Western one and a Japanese one. If the trial version of that game is downloaded 3 times, it means it has an internal regional block
The second way is similar to the first by downloading free dlc or buying cheap dlc for the games you want. If the game is global it will not let you buy the same DLC in the other 2 stores, if it is marked in both America and Europe as purchased and in the Japanese store that means that the Western game, if it is only purchased in the American store the game has internal regional block
The third way I use is to go to the pirate pages where they put the internal identifier of the game and the regions they belong to. This last way is the easiest, although some pirate pages have incomplete information and another disadvantage of this way is that you have to wait for the game to be released, or leaked.
These three ways kept me from buying XSEED/Marvelous games on Switch for example STORY OF SEASONS: Pioneers of Olive TownIt has an internal regional block due to having a different identifier in 4 regions (America, Europe, Japan and China), meaning that if you want to buy a DLC of this game it has to be from the same region where you bought your version or in the case of the spinoff called Rune Factory you will not be able to get the save files bonus if the internal game identifier is different for each region. Some Bandai games also have this problem, because Sword Art Online Hollow Realization and Sword Art Online Alicization Lycoris have different internal identification in America, Europe and Japan. But the intermediate called Sword Art Online Fatal Bullet is Western and Japanese.
Most developers use the same internal identifier in America and Europe (Atlus, Square Enix). So far I've only had problems with Bandai and XSEED. On the other hand, the games developed by Nintendo are mostly global, that is, they only have an internal identifier for all regions, at least in the case of the following franchises: Fire Emblem, Pokemon, Mario, Zelda.
The first way is that if the game has a trial version, try to download it at the same time from all stores. The result will depend on how many times the trial version has been downloaded. If the trial version is downloaded once it is a global game, if the trial version is downloaded twice it is most likely a Western one and a Japanese one. If the trial version of that game is downloaded 3 times, it means it has an internal regional block
The second way is similar to the first by downloading free dlc or buying cheap dlc for the games you want. If the game is global it will not let you buy the same DLC in the other 2 stores, if it is marked in both America and Europe as purchased and in the Japanese store that means that the Western game, if it is only purchased in the American store the game has internal regional block
The third way I use is to go to the pirate pages where they put the internal identifier of the game and the regions they belong to. This last way is the easiest, although some pirate pages have incomplete information and another disadvantage of this way is that you have to wait for the game to be released, or leaked.
These three ways kept me from buying XSEED/Marvelous games on Switch for example STORY OF SEASONS: Pioneers of Olive TownIt has an internal regional block due to having a different identifier in 4 regions (America, Europe, Japan and China), meaning that if you want to buy a DLC of this game it has to be from the same region where you bought your version or in the case of the spinoff called Rune Factory you will not be able to get the save files bonus if the internal game identifier is different for each region. Some Bandai games also have this problem, because Sword Art Online Hollow Realization and Sword Art Online Alicization Lycoris have different internal identification in America, Europe and Japan. But the intermediate called Sword Art Online Fatal Bullet is Western and Japanese.
Most developers use the same internal identifier in America and Europe (Atlus, Square Enix). So far I've only had problems with Bandai and XSEED. On the other hand, the games developed by Nintendo are mostly global, that is, they only have an internal identifier for all regions, at least in the case of the following franchises: Fire Emblem, Pokemon, Mario, Zelda.