Exactly the same reason why I don't invest a lot in SG. Moving your money back to MY AFTER your death could be an issue if your kid is not familiar with financial products.
Just an older perspective to TS - have the end-goal in mind, eg. Estate planning.
All the moving about to US / SG / etc brokerages & accounts - ensure it's worthwhile for your Will's Executor to file/execute your Will in those countries and retrieve
+
relevant Estate taxes, even if SG brokerage, it can be US Estate Laws U'll face like 45% taxed on anything above USD $60K.
Personally, i've moved my stuff back to "easier & cheaper" for my Will's Executor to perform their duties with less or no estate taxes.
Of course there will be some smarter folks saying to share userid & password with another or joint-account but.. look into the details and probabilities ya.
Executability when needed +legality + impact.
Note - i'm 49 this year and based on the local brokerage charges / fees on dividends, no biggie based on the amount i'm transacting. Thus, the end-goal is more important to me for my family. When younger, yup all those cost are quite a big % impact thus worthwhile to have accounts like OptionsXpress, TDAmeritrade, etc.
No absolute right / wrong ya - just sharing what i've done & thought - different strokes for different folks & different stages of life.