So long as the additional Stat has the bleed hole drilled, I don't see a problem as the OEM Stat is fitted with a ball valve anyway. (This allows fluid to expand or contract either way)
But Guys, don't expect the remote stat to run as hot as a correctly functioning OEM type.
88 deg on the cool return coolant through the OEM Stat is bound to give hotter results than 88 deg in the outlet from the cylinder head area.
Don't get me wrong, the Remote stat is a good economical mod but I fear will never work as well as the BMW design.
For that reason I am still offering a fitting service for both types!
Two BMW Stat install jobs have just come in for the New Year ..............for my sins