By the by, apparently, the later Xeno games redo the intended ideas of the undon episodes of the Xenogears eries. How true is that assertion?
Xenosaga is an alternate universe or refined expanded version of Episodes 1 of Perfect Works, with the original plan to be 6 games across three episodes instead of six, so Episode 1 and 2 being the war over the Zohar, then 3 and 4 being the Xenogears remake, then 5 and 6 being Episode 6. The plan failed after Episode 1 ran into development problems and had to be split across 1 and 2, at this point Takahashi left the project. They then restructured Xenosaga into 3 games covering just Episode 1, with it ending
with kos-mos floating towards a ringed planet presumably the Xenogears one, with the story having changed a lot from Gears and the episodic outline, but using the same framework and concepts. The Xenosaga trilogy is the closest visually to another Xenogears with a lot of direct references to Gears with characters appearances and names, and objects, but not really story beats.
Takahashi some time around 2006 was struck with the idea of two warring giants and that became Xenoblade, which was originally not a Xeno title at all, only becoming one at the behest of Iwata. It re-used some leftovers from Xenosaga with the Telethia being the Gnosis and the idea of predestined fate (which shows up a lot in 3 in regards to Zarathustra), but for the most part its disconnected from the greater series, only in hindsight does it become more obvious that all along there was still a lot of the Xenosaga concept framework at play, such as the UMN/Upper and Lower Domain, and a common theory is that they intended for the Zohar to appear at the end, but Nintendo/Monolith had hired an editor to help make the script approachable for more people which resulted in a lot of simplifcation, and a giant golden cross monolith appearing would be confusing to the Nintendo playerbase. This was then retconned for it to show up in a minor form in the Switch remaster.
Personally come Xenoblade X and later Xenoblade 2 I think they had dropped the idea of the episodes entirely and chose to instead re-use the overall plot and concepts instead. Xenoblade X specifically uses a lot of direct Xenosaga technology and terminology, which a lot of people missed at the time as the game had a lot of development troubles resulting in large story restructuring and cut content. The Japanese exclusive art book revealed that some of the mysterious enemy mech suits, intended for a larger role in the original script but only showing up as a time trial boss fight in the released game, actually use Logic Drive warp engines attached to them, the same tech used in Xenosaga. Abel's Ark from Xenosaga shows up in a flashback at the end, saying they came from another universe, but the implication of it being Abel's Ark is that they came from another instance of eternal recurrence. A machine translated datapad texture had a bunch of lore text of questionable canonicity (that is now assumed canon after X
E) that describes weapons that function the same was as Kos-Mos. The Skell power system functions the exact same as Slave Generators from Gears, something the Xenosaga mechs do as well. The actual story of the game though, other than Earth vanishing (a common occurrence across all the games) and landing on a new planet, is not really connected to the Xenogears themes or structure.
Xenoblade 2 is the combination of a love letter to shonen anime while also reusing and expanding on a lot of scrapped ideas from X's troubled development. It uses a lot of the Trinity ideas from Gears while also expanding the Slave Reactor transferal of data to and from the Zohar, and its the first Blade game where the Zohar proper appears.
Xenoblade 3 is the closest game to a Xenogears remake, the entire structure is basically the same as Xenogears with two lovers bound across time through reincarnation having to overcome the shadowy rule of an entity that feeds off humanity. There are a lot of changes but an incredible amount of story beats are the same, and Yasunori Mitsuda used a lot of Xenogears musical motifs throughout the soundtrack including the final boss. It builds a lot more Xenosaga esoteric ideas into it however.
Xenoblade X Definitive added new story that firmly plants it as a Xenosaga successor with clarifications and additions such as essentially the Gnosis, essentially the Zohar, essentially Zohar emulators, essentially the UMN and upper domain. So if the numbered blade games culminated in a new Xenogears, to me I see the X game (and possible sequels) as doing what they wanted to do with Xenosaga.
So essentially yeah the games carry on the themes and concepts of Gears, but they are further refined and changed as they go, rather than being stuck in the past forever doing perfect works, a major theme of Xenoblade 3, perhaps a reflection upon the series as a whole, further cemented by the DLC standalone story expansion for 3 being a reflection upon the series towards the end with a Vector Industries radio that drops memberberries towards the entire series as a whole, something the greater community (something that I do my best to avoid entirely) spent far too long arguing about game canonicity rather than seeing it as the self reflection on 25 years of games. It's no coincidence that Xenosaga, Xenoblade 3, and Xenoblade X DE all end on a new planet appearing, reaching towards the future in a meta sense.
