DGSD '81 was the first TVB adaptation of a Jin Yong story to make use of SFX to portray the powerful martial arts skills from the story. Between the beginning and end of the 1980s, SFX made gradual improvements. SFX technicians were capable of more "tricks" in 1989 than they were in 1981. Several years of technological improvements will give filmmakers more toys to play with.
That said, TVB did not use the same extent of SFX in its series progressively through the 1980s. Let's assume that on a scale of 1 to 10, "1" represents minimal use of SFX while "10" represents over-the-top, crazy use of SFX.
Here's the breakdown I get from the 1980s TVB series I've seen, in chronological order of production/release:
DGSD '81: 7
LOCH '82: 5
ROCH '83: 4
SPW '84: 10
DOMD '84: 2
HSDS '86: 5
I think I see a pattern here. I think that during the 1980s, TVB applied SFX to the adaptations as fit the level of martial arts seen in the corresponding novels. For example, DGSD, famous for its multiple LDA martial arts (and being the very first that TVB did with modern SFX), made relatively extensive use of SFX. LOCH, produced a year later, saw the SFX being scaled back a bit...perhaps because LOCH featured less powerful martial arts and less LDA? ROCH '83 used about the same (perhaps even slightly less) SFX than LOCH '82, but SPW '84...that was a gonzo lightshow of ridiculous proportions. From what I know of SPW, its martial arts are even more outrageous and outlandish than DGSD's (though not necessarily more powerful), so perhaps this is the reason that TVB went completely, over-the-top nuts with SFX on SPW '84? DOMD, being set in the early Qing Dynasty, did not require extensive use of SFX and hence, DOMD '84 only used level "2" SFX. HSDS '86, being a part of the CONDOR HEROES TRILOGY, used about the same amount of SFX as LOCH '82 and ROCH '83 (not going over the top like SPW '84 or even DGSD '81) because the peak martial arts level was fairly consistent throughout the CONDOR HEROES TRILOGY.