The situation you're describing is equivalent to paying your 5% in asset tax the normal way (by giving up 5% of the asset) and then saying "I love enron, let me take out a loan to buy stock with!" Buying stock with a loan is an obviously stupid move, and wanting to "stay invested" is nothing more than a rationalization. Keeping the same percentage of your wealth in the stock is already staying invested. Increasing the percentage for the sole purpose of keeping the same number of shares is a bad idea.

And this hypothetical me, having to pay a wealth tax, is way way over the line of needing a financial advisor, so that advisor will be telling me it's a bad idea to take out loans to buy stock.