I don't know if this is something feasible or cheap to implement. It is a 'nice to have', I can live without...
In Italian the use of apostrophe to shorten articles is common. E.g. allo inizio -> all'inizio
TXC marks as an error "all" but it is not an error *if followed by an apostrophe*. It is an error if followed by a space or another punctuation mark.
There are many other examples: quell'altro, sull'esperimento
I can put all of them in my dictionary, but this prevents detection of real errors like a missing apostrophe.