ubiquitin
“Although generally for “takanas Hashavim”we are meikel”
Agreed on the concept and in theory you are correct. However, allow me to elaborate, when it comes to ultra-sensitive issues as Ishus and Yichus. There is no definite p’sak or procedure and, cannot be, as the Geirus is entirely up to B’D, and these cases need guidance of Gedola Horaha, due to the gravity of the issue ruled as a case-by-case basis. see res. Divrei Chaim A”Hv vol 2 (ch. 36 at the end ). Gedolim have to make sure that the “heter” does not become abused as kind of a tool for all who just want to intermarry, it can only be used as a last resort, and that is up to the B’D to investigate and decide.
That is why in many cases, many will not permit it, as it became normal procedure and instead of being used as a ‘tekanos haShovin’ it became a Tikon L’evaryon’.