Hi David,
I know a bit about this but I would not call myself an expert.
There are a couple of important points to consider relating to the type of variable star.
First, if all you are interested in is timing, like eclipsing binaries, or detecting the outburst from an object, then a TG filter really should not matter.
When submitting observations to be compared with V filters, if the star has strong emission line features in the spectrum, then I think this can lead to larger differences between a TG and a V filter.
There is an option to submit TG filter observations in the BAA Photometry Database.
Cheers,
Andy