Is it true cash subscription for Unit Trusts allow rich investors to undercut retailers? Or can they spin off a new class of units for them?

Yes, such high net worth investors get a different level of status and along with it, one of the key beenfits is getting UT at lower cost, besides being offered a larger variety

Class of shares does not happen for rich investors commonly. It can happen like how buffett negotiated with Bank of Amercia to get preference shares (which had a unique set of T&C) ; but such matters happen less frequent in Singapore's settings​​​

Yes, there are various tools in the market to help bigger investors build more wealth at a lower cost.

For instance, AIA has launched an investment tool last year that engages the likes of global investment houses like BlackRock to help mass consumers achieve a similar outcome.

Here is everything about me and what I do best.