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Its not really about agreeing or not. You don't have to take my word for it, its widely studied and understood. Oxidation in the heat affected zone from welding creates embrittled areas. No ti framebuilder worth their salt will accept welds with any discoloration beyond a light straw. A bicycle frame with heavy oxidation is very likely to fail fairly quickly, embrittled areas produce stress risers and micro cracks which turn into full on cracks.

Its not impossible to get away with discoloration if you use really heavy wall tubing, however best practice in the vast majority of ti welding applications is to produce a colourless weld, or as close to that as possible. If you look at any of the best ti framebuilders, moots, bingham, enigma,seven, they all have pretty much colourless welds.
You do sometimes see fabricators purposefully heating up and discolouring custom supercar exhausts for aesthetic reasons. But these are non-structural parts so they can do whatver they want with them.

Read below if you're interested/dont believe me

https://www.excelco.net/welding-techniques/titanium-welding-unique-benefits-unique-challenges-unique-risks/

https://www.youtube.com/watch?v=TLbC5Qlpjgw

https://www.twi-global.com/technical-knowledge/job-knowledge/weldability-of-materials-titanium-and-titanium-alloys-024#:~:text=At%20temperatures%20above%20500%C2%B0,oxide%20generates%20an%20interference%20colour.