"Does anyone happen to know if using the Speedtouch & Bt Filters together can cause problems."
I very much doubt it. The filters are designed to a pretty generic standard. 2 of the pins of the BT device will be unused.
OnePlus 5 review
30 UK artists have created vibrant posters celebrating Pride London
iPad Pro 10.5in (2017) review
Comment connecter un MacBook à une TV ?