I have 3 mr beer kegs and I been using them for small batches. So far its been working well for me. I use a cane to get the beer in the bottling bucket because the spigot sucks. I want to remove the spigot and use a brass plug to seal it but In order to do so its gonna involve teflon tape.
...I could also solder the fittings together with 95/5 ... how about that with wort/beer?
The teflon itself won't be an issue as it is extremely unreactive. The only issue would be if you had a large excess of tape flapping around in there and folding over onto itself, etc. making it hard to sanitize.