I'm used to it, been a LTH in OPTI for over three years. Started buying there at 70p, bought more at all sorts of prices between 46 and 113, average still 70, price today around 52.
No you're not the only one. I bought in at the end of July @ 2p (now 20p), watched it up to over 70 and even gave a running commentary to the rest of the office! My colleague who knows diddly squat about investing advised me to sell out but I told him I was staying firmly put.
That said I invested for the non covid stuff, so the water testing and breath test will be a bit of a bonus (hopefully).
The way I understand it is that if you ask for and get allocated more shares than you can pay for with the money in your Hargreaves account, they will only buy you enough to use up the available funds. Couldn't see any mention of them selling other holdings to make up the difference.
One of the directors of Bridge4Health is Neil Davidson, also on their website is a celebrity endorsement from Rosemary Conley who was of course active in similar businesses a few years ago.