The way CHIP (savings account) raised on Crowdcube last year may have worked better. From memory this was (hopefully I’ve recalled this correctly):
First they had a private link for existing shareholders only. At this stage most investors were capped at investing a maximum of £1,200. This gave an opportunity for all existing shareholders to obtain shares, which could be EIS eligible. Because it was capped at this point there was no need to rush to invest.
Secondly, the pitch was opened up to the wider CHIP community with a similar £1,200 investment cap. Because it was still capped at this point there was no need to rush to invest either.
Thirdly, the pitch was opened up to everyone else and the cap removed, so existing investors could also top up their investment if they wanted and new investors could also participate.