I don't think there is anything wrong with a trade if you know what you are doing, have a risk limit & there is a repeatable process to it.
Franky was down on Thursday, London also opened down, but reversed on the last 30M. The issue I've with it is, how do you enter on this trade with very low risk, where would you place your stop, to be sure in your mind that you can accept that loss?
On Franky open, the outcome is very binary, if you are wrong on the direction, you are just wrong. But when you are trading few hours into London, if there is no repeatable pattern you trade during those hours (on most days the momentum has already faded, you get chop), you cannot do it every day.
Maybe you will be able to do it today, or another day. But you will be relying on your discretion for these trades, not a consistent pattern.
This will make it really hard to say with consistency at the end of the week or month, what is working or what is not.
For example, even if you were are buyer on the Franky open all year round, took 20 pips, with SL of 10 pips, maybe that even has an edge. You don't have to think or be emotional about it.
But what happens when you are doing something that you cannot repeat.
As always, if you can do within the risk control framework, that you walk away after certain loss limits being hit, you can still make it work.