I feel for you @mikewhite I work for a very large company that finally gave me an Apache server in 2014 - for the five years prior, it was ASP.net and IE6 only. I became quite proficient at stripping out PHP when possible and replacing with ASP (Yabdab’s form, for example), or working with developers on work-arounds (Joe helped me out on many occasions, as did Nimblehost). But, the stark reality is that RapidWeaver users are by and large on Apache - and so the developers follow suit.
My advice is to try really hard to get your institution to install an Apache server (it can be a virtual machine). If they don’t want it on their network, you could mention that your sites could be hosted elsewhere (at Chillidog, for example) and restricted by IP to folks behind your firewall.
The three happiest days of my employment were: the day I was hired; the day they finally gave me an Apache server (at the time I had over two dozen Rw sites up); and the day we ditched IE6 for IE11.