I appreciate your advice. When my mortgage is due, I will be in a position to pay off a large portion of it, reducing it to a level where it’s not really worth getting a mortgage (for neither me nor the banks). I’m also looking to move up the property ladder, so it helps to put all that equity to work somehow.

HELOC’s are very risky - in comparison to a Variable rate mortgae in that should the urge ever come and you want to convert into a fixed mortgage, there would be cost associate with this, whereas a variable mortgage, there would not be.
Discharge fee on the HELOC, cost for new mortgage - appraisal, legals, admin cost, etc.
As current rates go, you can get a lower rate with a Variable mortgage than a HELOC - and you can convert into a fixed rate with no cost - at most banks. It may not be on the radar now, but with constant discussion indicating when the Prime does go up, it will go back to historical norms of 5% on avg., I will not be surprised when the clients with HELOC’s come rushing back to the banks to get a fixed mortgage. The savings they may have had will be out the window.

And there is the human nature effect too - if you have room to use the HELOC - most people will. Spur of the moment purchases. When given the option to pay principle and interest payments or Interest only payments, client usually take the later. When given the option of paying $200 versus $1500.00 client typically go with the lower payment. Fast forward 5yrs in the future, and barely a dent is made into the principle.

Just my two cents from being in the mortgage business for many years.

I am literally counting the months until my 5-year fixed rate mortgage comes up for renewal, at which point I will switch to a HELOC (with another bank) to pay off the balance at a much lower interest rate.