In my opinion, it is prudent to account for another possible covid-response dip in markets. So factor in the possibility of having to inject cash if the collateral value of your securities dips.You should also account for the possibility of companies not paying out a dividend (for example, a number of good dividend companies didn’t pay a dividend this year). In other words, don’t use more secured financing than you can realistically afford in a worst-case scenario. The last thing you want is to be forced out of your position at a loss.
If you can earn a decent yield on your cash, that is obviously an incentive to use Lombard loans and keep your cash available.
My advice would be different for day traders. In that case, Lombard loans provide a great tool for bridging short-term liquidity gaps caused by settlement cycles, in my opinion.