Why haven't you got it yet? Mocha Hitfilm for Express
If you're using Hitfilm Express for anything that requires any kind of masking or roto work - and if you're not, what are you even using Hitfilm for? - then the mocha Hitfilm plugin at 33% off is definitely worth getting. As mocha Pro has recently been updated to include a magnetic edge-following tool and had a UI refresh, there's a slim possibility that Hitfilm's mocha might get that added at some point too.
Note: Hitfilm mocha for £/$/€29 in the current sale is not the same as mocha Pro at 10x the price (but not 10x the features, IMO). Even if it's still the current one for a while: manual roto sucks and like all your other plugins: it carries over to every future version of Hitfilm Express; so if/when mocha does get a refresh: you'll get that for free.
Although it's a 'reduced features' version, it has more than the version you get bundled with Vegas, or After Effects (3d Camera solve for one thing) and with the Corner Pin export feature you can do things like in this thread, or more normal things than political sniping: https://fxhome.com/forum/discussion/comment/119443