Subject: Re: OT: IBKR portfolio screen
I am using it with browser, not the app...

Though maybe you have a reason not to run it, this is easily solved by running their TWS app (Windows + Java).
Even if you don't use it for trading, it has precisely what you're looking for: gain/loss to date (% or dollars), current price, gain/loss today (% or dollars).
You can see it for your whole portfolio, or any subset of tickers you want to put on a page. You can put in header rows to separate sections on the page, and it will give you subtotals of the gain/loss amounts for each section.

It's daunting looking at first, but only for an hour or two.

Jim