Probably you mean “Number of lots to be traded” instead of Lot Size.

The formula for calculating the long position’s profit is:
Position’s Profit / Loss = (Close Price - Open Price) * Number of lots.

As I see, you want to remove “Number of lots” from the formula. If we do so, it will be not possible to calculate correctly the cases when we add to a position.

Example:

Open long 1 lot at 1.50;
Add 1 lot at 1.60;
Close all (2 lots) at 1.70.

According to the programs logic the profit will be: 20 + 10 = 30 pips.

Another example:
Open long 1 lot at 1.50;
The price goes up and returns back to 1.50 and the strategy adds 1 lot at 1.50;
Closing at 1.70.

The profit must be 20 + 20 = 40pips.

That situation is exactly the same as we were open 2 lots initially. So the profit must be the same;
20 pips * 2 lots = 40 pips profit.
If we apply the logic you propose, the program will show profit 20 pips.

I think no correction of the program’s logic is necessary. If you want to see the profit / loss without “Number of lots” correction, use 1 lot for entry and forbid the adding and reduction.

PS.
If you think you are right, that may be a bug. Please publish an example.

when showing the loss/win etc. in Pips (Account - Information in Pips), one strategy (as an example) has 860 pips profit. Now when changing the fixed (I don´t add or anything, just trade a fixed lot size) the lot-size for trades (double it for example), the same strategy has now won double the Pips. This doesn´t make sense at all since the strategy can´t create more pips with a higher lot-size, only when displaying the profit in Dollar/Euro the amount would double, but the profit in pips would stay the same as it has no relation to a Dollar/Euro value at all. However, it still doubles or decreases when changing the Lot-Size, which makes no sense at all.

Hope this get´s fixed as this is seriously wrong calculated.