Yes that is true about the Ta-152. As for the Ta-154 yes it did see service but I dont know how many were built or how extensive the service was here is some info on it.
Origin: Focke-Wulfe Flugzeugbau GmbH
Models: V1 to V15, A and C series
Type: Night and All-weather fighter
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POWERPLANT:
Type: Junkers Jumo inverted-vee-12 liquid-cooled
Number: 2
Horsepower:
V1, 2 - Jumo 211N - 1,520hp
V3-15, A-1 - Jumo 213E - 1,750hp
C - Jumo 213A - 1,776hp
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DIMENSIONS
Span: 16.00m
Length: 12.56m
Height: 3.60m
WEIGHTS:
Empty: 1810kg (3,990lbs.)
Maximum Loaded 2500kg (5,512lbs.)
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PERFORMANCE:
Maximum speed 670km/h (416mph)
Service Ceiling: 11,000m (36,090ft)
Range: 900km (559 Miles)
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ARMAMENT:
Two MG 17 and a 20mm MG/FF