Possible time savings
Cut introduction to 15 minutes (5 min saved)
Open voting to 30 min only (15 min savings)
Cut jury presentation to 25 min (10 min s.)
That saves only 30 minutes and much more is not possible as you have to wait until televotes come in and are counted. To cut vote vote presentation by country completely would kill ESC. Even if they would have 100% televotes there is time needed to collect televotes from each country. A Grand Final under 3:40 is impossible.
Introduction: I suggest having the Eurovision ident / Te Deum
Marche en rondeau, followed by a 2-minute pre-recorded opening seqence. National commentators (e.g. Graham Norton for BBC One in the UK) can talk over this. Afterwards there is a seamless transition to the venue, whereby you have a voice-over (heard by audience and viewers in all countries), who introduces the flag parade. Have the 26 artists enter in performance order (artist of host country may be required to enter last at host broadcaster's discretion). Don't pad the flag parade with extra acts at certain points like they've done recent years. When the parade ends, the hosts appear, and they give an introductory speech. The whole thing from Eurovision ident to the start of the first postcard should thus be 10 minutes.
Lines open for televoting: I agree, 30 minutes should be sufficient. It should be like this:
1st recap
1st interval act
2nd recap
2nd interval act
3rd recap (meanwhile clear stage and put lectern in place, thereby removing the need for another prerecorded filler between "Stop voting now" and start of jury voting announcent.
Jury voting: spokesperson says "Good evening <host city>" in English or French. Saying "Thank you for an amazing show" would be fine as a filler whilst the 1, 2, 3, 4, 5, 6, 7, 8, 10 point recipients are displayed at the bottom of the screen for 20 seconds (that should be enough for most viewers). Those 9 countries have their scores updated / change postion on the scoreboard, and the spokesperson announces the 12 point recipient in English or French (host repeats in opposite language). The spokesperson can't give other unnecessary "drivel", e.g. "play Ja Ja Ding Dong, 12 points to Ja Ja Ding Dong" before saying "12 points to (e.g.) France." Each spokesperson should be able to do their complete turn in 45 seconds. With up to 44 countries announcing (I think 44 is the maximum permitted number of entries), that should shave a few minutes off announcing the jury voting results.
Televoting totals: don't have long pauses before announcing the next finalist's total. I remember in 2021, when they got to the countries which placed high in the jury vote, I shouted "Come on, tell us how many points <country> has got". Long pauses drag it out unnecessarily. Exceptionally they could restrict pauses to the last 3 countries (when they've got the split screen up).
Reprise: midway through start scrolling the credits, so at the end of the performance there's the Eurovision ident and Te Deum.