A proportion of FTers have reported getting them, and another proportion have reported not getting them. To a degree it is going to regulate itself - the First Lounge can get very full anyway and if there was a lot more guesting it wouldn't be worth going there, it would be too crowded. You can use the First Check-in, that aspect is OK, and of course there is a Fast Track next to it on the other side to the First Wing, it wouldn't slow you down very much but admittedly it's less serene than the First Wing security channel.

One thing for you to consider, there is a chance your service will leave from T5B, but even if it is not, and you arriving at T5 with plenty of time before departure, then perhaps consider going to Galleries Club T5B. It has the same food as the main lounges, but it is widely admired in this forum as one of Heathrow's better lounges. They have recently slightly improved the catering there, including more hot breakfast items before 11:00 hrss, and salad options in the morning too. If you do this, you best have a look at the passageway guide for departing passengers in the Dashboard.