Exiting an investment property in a OPM vs CA scenario - Should I continue to rent out for OPM or should I sell it for CA (but losing OPM)?

Hi. I have an investment property (~$1mil) that I rent out at $2500 per month. I like to seek your opinion as to when to exit a property, particularly when talking about using OPM (Other people's money) concept. e.g. Let's say there is a capital appreciation of $200K after 5 years, do I (1) cash out and lose using OPM or (2) should I continue on even when CA will be stagnant since OPM is paying off the mortgage. I don't know how to calculate so any advice will be great.

I will sell

Assume is a residential property, new launch condo?
I think the most effective & prudent way to invest in SG property.

Is to buy, hold 2-3 years, then sell, then upgrade bigger.
The profit from the previous sale, pay off partial of the new condo. Then the cycle continue,until around 50. Then downgrade to a resale HDB (last property). VS the sell 1 buy 2 scheme.

Rental is just additional $$$ while you holding your property.

I think that is the best retirement plan. Every $$$ u pay the loan, u will get back when u sell it. It become an force saving, instead of paying to insurance company, u pay to bank. In additional, u r paying for a roof over your head instead of a paper.