https://www.newsweek.com/lego-faces-boycott-calls-over-transgender-building-sets-1803239
And Flora and M&S (after they ended their sponsorship with MN), the NSPCC (tbh not sure how you boycott a child protection org), New Zealand, Bud, Nike and most sports brands, Primark because they permit transpeople to use the changing rooms as is their legal right under the EA, Wagamama(for displaying a flag), Target, and now Lego. And there's probably a bunch of others I missed.
And yes I have seen posts on here where members complain en-mass to shops that have a pride flag in the window. The one with the triangle part; which you may be interested to know also has colours representing people of colour, people affected by AIDs as well as the trans community.
If you boycott ever single place that remotely shows any support for gay+trans people that must make shopping difficult? June is coming up so expect to see a lot more pride flags.
If I ran a business I would keep a pride flag up all year round, if it makes me lose 0.2% of customers who are gender critical I'd be more than happy with that, at least it would help keep my premises a safe space.